CN114552380A - Resonant cavity, laser unit, chip, laser, forming method and laser radar - Google Patents

Resonant cavity, laser unit, chip, laser, forming method and laser radar Download PDF

Info

Publication number
CN114552380A
CN114552380A CN202011351156.6A CN202011351156A CN114552380A CN 114552380 A CN114552380 A CN 114552380A CN 202011351156 A CN202011351156 A CN 202011351156A CN 114552380 A CN114552380 A CN 114552380A
Authority
CN
China
Prior art keywords
mirror
resonant cavity
laser
forming
reflective
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202011351156.6A
Other languages
Chinese (zh)
Inventor
林炳成
费嘉瑞
向少卿
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hesai Technology Co Ltd
Original Assignee
Hesai Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hesai Technology Co Ltd filed Critical Hesai Technology Co Ltd
Priority to CN202011351156.6A priority Critical patent/CN114552380A/en
Priority to PCT/CN2021/112715 priority patent/WO2022110909A1/en
Publication of CN114552380A publication Critical patent/CN114552380A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
    • H01S5/183—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
    • H01S5/18361—Structure of the reflectors, e.g. hybrid mirrors
    • H01S5/18363—Structure of the reflectors, e.g. hybrid mirrors comprising air layers
    • H01S5/18366—Membrane DBR, i.e. a movable DBR on top of the VCSEL
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
    • H01S5/183—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
    • H01S5/2004—Confining in the direction perpendicular to the layer structure
    • H01S5/2009—Confining in the direction perpendicular to the layer structure by using electron barrier layers
    • H01S5/2013—MQW barrier reflection layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/32—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures
    • H01S5/323—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/32—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures
    • H01S5/323—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser
    • H01S5/32308—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser emitting light at a wavelength less than 900 nm
    • H01S5/32316—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser emitting light at a wavelength less than 900 nm comprising only (Al)GaAs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Geometry (AREA)
  • Semiconductor Lasers (AREA)

Abstract

A resonant cavity, a laser unit, a chip, a laser, a forming method and a laser radar are provided, wherein the resonant cavity comprises: an active region; first and second mirrors located on both sides of the active region in a laser propagation direction, wherein the first mirror includes: the reflective device comprises a first reflecting part and a second reflecting part positioned between the first reflecting part and the active region, wherein the material of the second reflecting part comprises first doping ions, the material of the second reflecting mirror comprises second doping ions, and the conductivity types of the first doping ions and the second doping ions are opposite. The resonant cavity can reduce the light absorption rate while ensuring the electrical conductivity, is beneficial to reducing the loss of the resonant cavity and enhancing the luminous intensity.

Description

Resonant cavity, laser unit, chip, laser, forming method and laser radar
Technical Field
The invention relates to the field of lasers, in particular to a resonant cavity, a laser unit, a chip, a laser, a forming method and a laser radar.
Background
Laser radar is a range finding sensor commonly used, has characteristics such as detection range is far away, resolution ratio is high, receive environmental disturbance little, and the wide application is in fields such as intelligent robot, unmanned aerial vehicle, unmanned driving. In recent years, the automatic driving technology has been rapidly developed, and the laser radar has become indispensable as a core sensor for distance sensing.
The performance of a laser, which is one of the core components of a laser radar, has a great influence on the performance of the laser radar. A conventional Vertical Cavity Surface Emitting Laser (VCSEL) employs an N-type doped substrate, and light emitted from an active region needs to be emitted through a Distributed Bragg Reflector (DBR). Among them, the DBR needs to be highly doped to improve its conductivity.
For a front-emitting VCSEL, the P-type highly doped DBR absorbs light more, resulting in a larger loss of light energy. In the back-emitting VCSEL, light is emitted from the N-type highly doped DBR direction. Compared with the P-type doped DBR, the N-type doped DBR has lower doping concentration and relatively lower light absorption, and the back-emitting VCSEL can be combined with a Flip Chip (Flip Chip) process and realize Micro-lens (Micro-lens) integration. Therefore, in recent years, back-emitting VCSELs have been gaining attention.
However, even in the back-side-emitting VCSEL, the highly N-doped DBR and the highly N-doped substrate absorb part of the light, which causes a problem of a decrease in the emission intensity of the back-side-emitting VCSEL.
Disclosure of Invention
The invention aims to provide a resonant cavity, a laser unit, a chip, a laser, a forming method and a laser radar, so that the problem of reduction of luminous intensity caused by absorption of light rays is solved while high conductivity is ensured.
To solve the above problems, the present invention provides a resonant cavity, comprising:
an active region; first and second mirrors located on both sides of the active region in a laser propagation direction, wherein the first mirror includes: the reflective device comprises a first reflecting part and a second reflecting part positioned between the first reflecting part and the active region, wherein the material of the second reflecting part comprises first doping ions, the material of the second reflecting mirror comprises second doping ions, and the conductivity types of the first doping ions and the second doping ions are opposite.
Optionally, the doping concentration of the second reflective portion is greater than the doping concentration of the first reflective portion.
Optionally, the material of the first reflective portion is an intrinsic material.
Optionally, the first mirror and the second mirror are distributed bragg mirrors.
Optionally, the number of cycles of the first reflection portion is greater than or equal to the number of cycles of the second reflection portion.
Optionally, the ratio of the number of cycles of the second reflective portion to the first reflective portion is in a range of 1:1 to 1: 10.
Optionally, the ratio of the number of cycles of the second reflective portion to the first reflective portion is in a range of 1:2 to 1: 5.
Optionally, in at least one of the second mirror and the second reflective portion, a doping concentration of a material on a side close to the active region is less than a doping concentration of a material on a side far from the active region.
Optionally, the doping concentration of at least one material of the second mirror and the second reflective portion is gradually decreased along a direction toward the active region.
Optionally, the active region has a first surface and a second surface opposite to each other, and a direction of the second surface pointing to the first surface is consistent with a current direction; the resonant cavity further comprises: a current confinement layer on at least the second surface.
Optionally, the current confinement layer includes: the current limiting layer comprises conductive areas and insulating areas filled between the conductive areas, wherein the conductive areas penetrate through the current limiting layer along the current flowing direction.
Optionally, the current confinement layer of the insulating region is made of an oxide; the material of the current confinement layer of the conductive region is a semiconductor compound.
Optionally, the current confinement layer is formed by oxidizing a semiconductor compound, the oxidized semiconductor compound being used to form the insulating region, and the non-oxidized semiconductor compound being used to form the conductive region.
Optionally, the projection of the conductive region on the surface of the active region is located at the geometric center of the active region.
Optionally, the method further includes: a substrate located on a side of the first mirror away from the active region, or on a side of the second mirror away from the active region.
Optionally, the mirror close to the substrate is a first mirror.
Optionally, the direction of the second mirror pointing to the first mirror is consistent with the laser propagation direction.
Optionally, the substrate is made of a semi-insulator material or a doped semiconductor material.
Optionally, the doped semiconductor material is one of N, P type doped GaAs, InP, GaSb, or InSb.
Optionally, the active region comprises a plurality of quantum wells.
Optionally, the quantum well is an InGaAs/GaAs quantum well or an InGaAs/GaAsP quantum well.
Optionally, the active region includes a plurality of active portions; the resonant cavity further comprises: a tunneling layer between adjacent active portions.
Optionally, the tunneling layer is located between the current confinement layer and the active portion; alternatively, a current confinement layer is located between the tunneling layer and the active portion.
Optionally, the method further includes: a current conducting layer electrically connected with the second reflective portion.
Optionally, the current conducting layer is located between the first reflective portion and the second reflective portion.
Optionally, a material of at least one of the first reflection part and the second reflection part is different from a material of the current conduction layer.
Optionally, a material of the current conducting layer is different from a material of the second reflecting portion.
Optionally, a material of the current conducting layer includes a first doping ion, and a doping concentration of the current conducting layer is greater than a doping concentration of the second reflecting portion.
Optionally, the first reflector further includes: a third reflective portion on a surface of the current conducting layer facing the first reflective portion, a material of the third reflective portion including first dopant ions.
Optionally, the doping concentration of the third reflective portion is greater than the doping concentration of the second reflective portion.
Optionally, the number of cycles of the third reflective portion is in a range of 1 to 2.
To solve the above problems, the present invention provides a laser unit including:
a resonant cavity, the resonant cavity being a resonant cavity of the present invention; a first electrode electrically connected to the resonant cavity; a second electrode electrically connected with the resonant cavity.
Optionally, in a plane perpendicular to the propagation direction of the laser light, the laser unit includes a core region and an extension region; the resonant cavity is located within the core region.
Optionally, the current conducting layer extends into the extension region; the first electrode is in contact with the current conducting layer of the extension region.
Optionally, the first electrode is located on a surface of the current conducting layer of the extension region facing the second mirror.
Optionally, a thickness of the current conducting layer of the extension region is less than or equal to a thickness of the current conducting layer of the core region.
Optionally, a thickness of the current conducting layer of the extension region is less than a thickness of the current conducting layer of the core region; the current conducting layer is stepped toward a surface of the first electrode.
Optionally, the third reflective portion extends to the extension region.
Optionally, the first electrode is in contact with a third reflective portion of the extension region.
Optionally, the first electrode is located on a surface of the third reflective part of the extension region facing the second mirror.
Optionally, a thickness of the third reflective portion of the extension region is less than or equal to a thickness of the third reflective portion of the core region.
Optionally, the thickness of the third reflective portion of the extension region is smaller than the thickness of the third reflective portion of the core region; the third reflecting portion is stepped toward the surface of the first electrode.
Optionally, the second electrode is located on a side surface of the second mirror away from the active region.
To solve the above problems, the present invention provides a laser chip, including:
one or more laser units, the laser units being the laser units of the invention; a first contact layer electrically connected to the first electrode; a second contact layer electrically connected with the second electrode.
Optionally, in a plane perpendicular to the propagation direction of the laser light, the laser chip includes a first region and a second region electrically isolated from the first region; the one or more laser units are located in the second region; the first contact layer is positioned in the first area; the second contact layer is located in the second region.
Optionally, the first region surrounds the second region.
Optionally, the directions of the second mirrors of the plurality of laser units pointing to the first mirror are all the same; the second contact layer is in contact with the second electrodes of the plurality of laser units.
Optionally, in the laser propagation direction, the first contact layer and the second contact layer are located on the same side of the laser chip.
Optionally, in one or more laser units, the first electrodes of the one or more laser units are connected; the first contact layer is electrically connected to the first electrode through an interconnect structure.
Optionally, the plurality of laser units include: an edge laser unit and a center laser unit, the edge laser unit being located between the center laser unit and the first region; the interconnection structure is electrically connected with the first electrode of the edge laser unit close to the first area.
To solve the above problems, the present invention provides a laser including:
the laser chip is the laser chip of the invention.
Optionally, the method further includes: and the beam shaping element is positioned on the light path of the laser generated by the laser chip.
Optionally, the beam shaping element is located on a surface of the substrate remote from the active region.
Optionally, the beam shaping element and the substrate are of an integral structure.
Optionally, the beam shaping element is: at least one of a microlens array and a nanopillar structure array.
Optionally, the laser is a vertical cavity surface emitting laser.
To solve the above problems, the present invention provides a laser radar including:
a light source comprising the laser of the present invention.
In order to solve the above problems, the present invention provides a method for forming a resonant cavity, comprising:
providing a substrate; forming a first mirror, an active region, and a second mirror on the substrate, wherein the first mirror and the second mirror are located at both sides of the active region in a laser propagation direction, wherein the first mirror includes: the reflective device comprises a first reflecting part and a second reflecting part positioned between the first reflecting part and the active region, wherein the material of the second reflecting part comprises first doping ions, the material of the second reflecting mirror comprises second doping ions, and the conductivity types of the first doping ions and the second doping ions are opposite.
Optionally, the step of forming the first mirror, the active region, and the second mirror includes: and sequentially forming the first reflector, the active region and the second reflector on the substrate.
Optionally, a current conducting layer is arranged between the first reflecting part and the second reflecting part; the step of forming the first mirror, the active region and the second mirror comprises: forming a first reflective material layer, an active material layer and a second reflective material layer on the substrate; etching the stack of the first layer of reflective material, the layer of active material, and the layer of second reflective material to form the resonant cavity; the step of forming the resonant cavity by etching comprises the following steps: and etching by taking the current conducting layer as an etching stop layer.
Optionally, the first reflector further includes: a third reflective portion on a surface of the current conducting layer facing the first reflective portion, a material of the third reflective portion including first dopant ions; and in the step of forming the resonant cavity by etching, etching is carried out along the direction of the current conducting layer pointing to the first reflecting part.
To solve the above problems, the present invention provides a method for forming a laser unit, including:
forming a resonant cavity, wherein the resonant cavity is formed by adopting the forming method of the invention; forming a first electrode electrically connected to the resonant cavity; forming a second electrode electrically connected to the resonant cavity.
Optionally, the method further includes: after the first electrode and the second electrode are formed, the substrate is removed.
In order to solve the above problems, the present invention provides a method for forming a laser chip, including:
forming one or more laser units, wherein the laser units are formed by the forming method; forming a first contact layer electrically connected to the first electrode; and forming a second contact layer electrically connected with the second electrode.
Optionally, the first contact layer and the second contact layer are formed in the same process.
In order to solve the above problems, the present invention provides a method for forming a laser, including:
and forming a laser chip, wherein the laser chip is formed by adopting the forming method of the invention.
Compared with the prior art, the technical scheme of the invention has the following advantages:
because first speculum includes first reflection part and second reflection part, wherein has first doping ion in the second reflection part, has second doping ion in the second reflector, consequently makes and reduces the average doping concentration of first speculum becomes possible, can reduce the absorptivity of light when guaranteeing the electric conductivity ability, is favorable to both guaranteeing electric conductivity ability, reduces the loss of light again, is favorable to strengthening luminous intensity.
In an alternative of the present invention, the doping concentration of the second reflective portion is greater than the doping concentration of the first reflective portion, even the material of the first reflective portion may be an intrinsic material, that is, the material of the first reflective portion is not doped, so that the absorption rate of the first reflective portion to the excited light can be effectively reduced, and the second reflective portion closer to the active region can ensure high conductivity, so as to reduce the loss of the resonant cavity while ensuring high conductivity, and facilitate enhancement of the luminous intensity.
In an alternative aspect of the invention, the number of cycles of the first reflective portion is greater than or equal to the number of cycles of the second reflective portion. The number of cycles of the second reflecting part with the first doped ions is controlled, the average doping concentration of the first reflecting mirror can be effectively controlled, the total doping amount can be effectively reduced, the conductive performance can be guaranteed, meanwhile, the absorption rate of light can be effectively reduced, the loss of a resonant cavity can be reduced, and the luminous intensity can be enhanced.
In an alternative aspect of the present invention, a ratio of the number of cycles of the second reflection part to the first reflection part is in a range of 1:1 to 1: 10; even the ratio of the number of periods of the second reflective portion to the first reflective portion is in the range of 1:2 to 1: 5. The proportion of the cycle number of the second reflecting part to the cycle number of the first reflecting part is controlled, so that the local concentration of doped ions can be controlled to ensure the conductivity, the total amount of the doped ions is reduced to reduce the loss, and the difficulty of the manufacturing process of the reflector is reduced.
In an alternative aspect of the invention, a doping concentration of a material in at least one of the second mirror and the second reflective portion on a side close to the active region is smaller than a doping concentration of a material on a side far from the active region; the doping concentration of at least one material of the second mirror and the second reflective portion is gradually decreased in a direction toward the active region. The method for enabling the doping concentration to be non-uniformly distributed can ensure the conductivity and reduce the doping concentration of the partial reflector close to the active region, thereby reducing the light absorption rate of the reflector near the active region, being beneficial to reducing the light intensity loss of the active region and enhancing the luminous intensity.
In an alternative aspect of the present invention, a current confinement layer, a conductive region and an insulating region filled between the conductive regions are further disposed on a surface into which the active region current flows, wherein the conductive region penetrates through the current confinement layer along a current flowing direction. The current limiting layer can limit the distribution range of current and inhibit the current dispersion effect, so that the current density of a light-emitting region in the active region is increased to improve the gain.
In the alternative of the invention, the material of the current limiting layer of the insulation region is oxide; the current limiting layer of the conductive region is made of a semiconductor compound; the current confinement layer is formed by oxidizing a semiconductor compound, the oxidized semiconductor compound forming the insulating region, and the non-oxidized semiconductor compound forming the conductive region. The method for forming the current limiting layer by oxidizing the semiconductor compound can effectively ensure the surface flatness of the formed current limiting layer to obtain a flat interface on one hand, and can effectively reduce the internal stress of the formed current limiting layer to reduce the influence on light on the other hand.
In an alternative aspect of the present invention, in the current confinement layer, a projection of the conductive region on the surface of the active region is located at a geometric center of the active region. The arrangement mode can effectively ensure the current distribution uniformity, thereby ensuring the beam quality of the resonant cavity.
In the alternative scheme of the invention, the reflector close to the substrate is the first reflector, so that the first reflector comprising the first reflecting part and the second reflecting part is formed in the process of forming the resonant cavity, the difficulty of the forming process can be effectively reduced, and the improvement of the structure quality and the manufacturing yield is facilitated.
In an alternative aspect of the invention, the direction in which the second mirror points toward the first mirror coincides with the laser propagation direction. The generated light rays are emitted from the first reflector, the absorption of the reflector on the laser emitting path to the light rays can be reduced, the energy loss of the light rays can be reduced, and the luminous intensity can be enhanced.
In an alternative aspect of the present invention, the active region includes a plurality of active portions having a tunneling layer therebetween. The method for realizing series connection of the active parts by utilizing the tunneling layer to form the active region can provide flexibility of active region design, gain superposition of the active parts in the active region is beneficial to improving resonant cavity gain, the tunneling layer utilizes quantum tunneling effect to reduce potential barrier between adjacent active parts, and quantum efficiency of the active region is increased to increase resonant cavity gain and improve output optical power.
In an alternative aspect of the present invention, the resonant cavity further includes a current conducting layer electrically connected to the second reflection portion, the current conducting layer being located between the first reflection portion and the second reflection portion, and enabling connection of the second reflection portion to an external circuit to form a current path of the resonant cavity.
In an alternative aspect of the present invention, a material of at least one of the first reflection part and the second reflection part is different from a material of the current conduction layer; the material of the current conducting layer is different from the material of the second reflecting portion. Forming the current conducting layer from a different material than at least one of the first and second reflective portions enables the current conducting layer to act as an etch stop layer during formation of the resonant cavity.
In an alternative aspect of the present invention, a material of the current conducting layer includes first doping ions, and a doping concentration of the current conducting layer is greater than a doping concentration of the second reflecting portion. The current conducting layer adopts higher doping concentration, so that the resistance can be effectively reduced, and the conductivity can be improved.
In an alternative aspect of the present invention, the first reflecting mirror further includes: a third reflective portion on a surface of the current conducting layer facing the first reflective portion, a material of the third reflective portion including first dopant ions. The third reflecting layer can effectively ensure the conductivity when over-etching occurs.
In an alternative aspect of the present invention, the doping concentration of the third reflective portion is greater than the doping concentration of the second reflective portion, and the period of the third reflective portion is in a range of 1 to 2. The third reflecting part with high doping and few cycles can improve the conductivity of the third reflecting part, can control the absorption of the third reflecting part to light rays, and can realize both high conductivity and low absorptivity.
In an alternative of the laser unit according to the present invention, the current conducting layer of the first electrode on the extension region faces the surface of the second mirror, so that the first electrode and the second electrode can face the same side, thereby reducing the process difficulty of disposing a subsequent contact layer.
In an alternative of the laser chip of the present invention, the first contact layer and the second contact layer are located on the same side of the laser chip in the laser propagation direction. Therefore, the laser chip is suitable for the manufacturing process of the flip chip so as to avoid metal routing, avoid an additional inductance effect and be beneficial to improving the response speed of a device.
In the alternative of the laser, the beam shaping element and the substrate are of an integral structure, so that the beam shaping element can be directly integrated on a laser chip, and the laser is favorable for improving the integration level and reducing the size of equipment.
Drawings
FIG. 1 is a schematic cross-sectional view of a VCSEL unit;
FIG. 2 is a schematic cross-sectional view of another VCSEL unit;
FIG. 3 is a schematic cross-sectional view of a resonant cavity according to an embodiment of the present invention;
FIG. 4 is a schematic cross-sectional view of another embodiment of a resonant cavity of the present invention;
FIG. 5 is a schematic cross-sectional view of a resonator according to yet another embodiment of the present invention;
FIG. 6 is a schematic cross-sectional view of a laser unit according to an embodiment of the present invention;
FIG. 7 is a schematic cross-sectional view of another embodiment of a laser unit of the present invention;
FIG. 8 is a cross-sectional view of a laser chip according to an embodiment of the present invention;
FIG. 9 is a schematic diagram of a top view along direction A of the laser chip embodiment shown in FIG. 8;
FIG. 10 is a schematic top view of a laser chip according to another embodiment of the present invention;
FIG. 11 is a schematic diagram of a laser according to an embodiment of the present invention;
fig. 12 is a schematic structural diagram of another embodiment of the laser of the present invention.
Detailed Description
As is known from the background art, the VCSEL has a problem that light is absorbed and the emission intensity is reduced while ensuring high conductivity. The reason for the problems of light absorption and luminous intensity reduction is analyzed by combining the structure of the VCSEL:
referring to fig. 1, a schematic cross-sectional structure of a VCSEL unit is shown.
The VCSEL laser chip includes a plurality of VCSEL units, and as shown in fig. 1, in the process of forming the VCSEL laser chip, an N-type doped DBR11, an active region 12, a current confinement layer 13, and a P-type doped DBR 14 are generally epitaxially grown on an N-type doped substrate 10 in sequence. After the epitaxial growth is completed, the VCSEL units are formed through a semiconductor manufacturing process, an annular P-type electrode 15 is prepared on the top layer of the P-type doped DBR 14 of each VCSEL unit, and an N-type electrode 16 is prepared on the bottom of the VCSEL laser chip.
Multiple VCSEL units on a VCSEL laser array chip may be driven with a common cathode. In each VCSEL unit, current is injected into the active region 12 via the P-type electrode 15; the material of the active region 12 emits light after being subjected to laser radiation, resonates in the resonant cavity formed between the P-type DBR 14 and the N-type DBR11, and forms an intense beam having the same propagation direction and the same frequency and phase.
The active region 12 of the VCSEL laser chip is very thin and the cavity length is only of the wavelength order, which reduces losses for lasing, so that the DBR constituting the cavity must have a significant number of layers to increase the reflectivity of the DBR.
A typical DBR includes high refractive index thin films and low refractive index thin films alternately arranged in the DBR, wherein the high refractive index thin films and the low refractive index thin films each have a thickness of 1/4 wavelengths, and a high reflectance expected by design is obtained by arranging the thin films for several tens of periods. Wherein, one layer of high refractive index film and one layer of low refractive index film are a period.
DBRs in VCSEL laser chips are fabricated using thin films of semiconductor materials, such as AlxGa1-xAs/Al1-yGayThe As films are sequentially and alternately arranged for 10-40 periods. Fig. 1 shows a front-emitting VCSEL unit in which the P-doped DBR has a small number of periods and a reflectivity slightly lower than the N-doped DBR, so that light is transmitted upward from the P-doped DBR to become usable laser light.
The larger the difference between the refractive indexes of the materials of the high-refractive-index film and the low-refractive-index film forming the DBR is, the higher the reflectivity is; on the other hand, a larger refractive index difference represents that the larger the band gap difference of the material itself is, the potential barrier is caused to the carriers, thereby causing the decrease of the conductivity; doping of the DBR material is therefore required to improve conductivity. However, the dopant ions in the DBR material can absorb or scatter photons, thereby causing optical energy loss, which is greater at higher doping concentrations.
Referring to fig. 2, a schematic cross-sectional structure of another VCSEL unit is shown.
An N-doped DBR 21, an active region 22, a current confining layer 23, and a P-doped DBR 24 are epitaxially grown in sequence on an N-doped substrate 20. Fig. 2 shows a back-emitting VCSEL unit, whereby the top layer of the P-doped DBR 24 of each VCSEL unit is provided with a P-type electrode 25 and the bottom of the VCSEL laser chip is provided with a ring-shaped N-type electrode 26. The laser light of the back-side-emitting VCSEL exits the substrate 20 as compared to the front-side-emitting VCSEL.
As shown in fig. 2, although the N-type doped ions have weaker absorption and scattering effects on photons than the P-type doped ions. However, even in the case of the back-emission VCSEL, the highly doped N-DBR 21 and the N-doped substrate 20 absorb part of light, which causes optical energy loss, so that it is difficult to obtain a sufficiently high emission intensity while the conventional back-emission VCSEL maintains high conductivity.
To solve the above technical problem, the present invention provides a resonant cavity, comprising: an active region; first and second mirrors located at both sides of the active region in a laser propagation direction, wherein the first mirror includes: the reflective device comprises a first reflecting part and a second reflecting part positioned between the first reflecting part and the active region, wherein the material of the second reflecting part comprises first doping ions, the material of the second reflecting mirror comprises second doping ions, and the conductivity types of the first doping ions and the second doping ions are opposite.
Because first speculum includes first reflection part and second reflection part, wherein has first doping ion in the second reflection part, has second doping ion in the second speculum, consequently makes to reduce the average doping concentration of first speculum becomes possible, can reduce the absorptivity of light when guaranteeing the electric conductivity of speculum, is favorable to both guaranteeing electric conductivity, reduces the loss of resonant cavity again, is favorable to strengthening luminous intensity.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
Referring to fig. 3, a schematic cross-sectional structure of an embodiment of a resonant cavity of the present invention is shown.
As shown in fig. 3, the resonant cavity includes: an active region 120; a first mirror 110 and a second mirror 140, the first mirror 110 and the second mirror 140 being located at both sides of the active region 120 in a laser propagation direction, wherein the first mirror 110 includes: a first reflective part 111 and a second reflective part 112 located between the first reflective part 111 and the active region 120, wherein a material of the second reflective part 112 includes a first doping ion, and a material of the second mirror 140 includes a second doping ion, and conductivity types of the first doping ion and the second doping ion are opposite.
The first reflecting mirror 110 includes a first reflecting portion 111 and a second reflecting portion 112, wherein the second reflecting portion 112 has a first doped ion therein, and the second reflecting mirror 140 has a second doped ion therein, so that it is possible to reduce the average doping concentration of the first reflecting mirror 110, and it is possible to reduce the light absorption rate while ensuring the electrical conductivity, which is beneficial to ensuring the electrical conductivity, and also reducing the light loss, and is beneficial to enhancing the luminous intensity.
In this embodiment, the resonant cavity is a resonant cavity of a vertical cavity surface emitting laser.
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
The active region 120 has a gain medium capable of realizing population inversion, and a stimulated radiation amplification effect is generated.
In some embodiments of the present invention, the active region 120 includes Multiple Quantum Well (MQWs) structures, i.e., the active region 120 is a Quantum well structure formed by alternately growing two thin films of materials with narrow band gap and wide band gap. For example, the active region 120 includes 2 to 3 groups of quantum well structures. For example, when the resonant cavity is that of a 940nm laser, the quantum well structure is an InGaAs/GaAs quantum well structure or an InGaAs/GaAsP quantum well structure.
The first reflector 110 is used to form a reflecting surface of the resonant cavity; the second mirror 140 is used to form another reflecting surface of the resonant cavity; light generated by the active region 120 travels back and forth between the first mirror 110 and the second mirror 140.
In the laser propagation direction, the first mirror 110 is located on one side of the active region 120, the second mirror 140 is located on the other side of the active region 120, and the first mirror 110 includes a first reflective part 111 and a second reflective part 112. The second reflecting part 112 is located between the first reflecting part 111 and the active region 120, that is, the first reflecting part 111 of the first reflecting mirror 110, the second reflecting part 112 of the first reflecting mirror 110, the active region 120, and the second reflecting mirror 140 are arranged in order of a straight line along the laser propagation direction. The material of the second reflective part 112 includes a first doping ion, and the material of the second reflective mirror 140 includes a second doping ion, and the first doping ion and the second doping ion have opposite conductivity types.
Dividing the first reflecting mirror 110 into a first reflecting portion 111 and a second reflecting portion 112 having first doping ions makes it possible to lower the first reflecting mirror 110; and the second reflecting portion 112 and the second reflecting mirror 140 close to the active region 120 both have doped ions therein, which can conduct electricity, so that the division of the first reflecting mirror 110 into the first reflecting portion 111 and the second reflecting portion 112 does not affect the formation of a current loop in the resonant cavity, and the second reflecting portion 112 and the second reflecting mirror 140 close to the active region 120 do not affect the resistance of the current loop in the resonant cavity, which does not affect the conducting performance of the resonant cavity, thereby reducing the light absorption rate while ensuring the conducting performance, being beneficial to reducing the loss of the resonant cavity, and being beneficial to enhancing the luminous intensity.
In some embodiments of the present invention, the doping concentration of the second reflective portion 112 is greater than the doping concentration of the first reflective portion 111. In this embodiment, the material of the first reflective portion 111 is an intrinsic material, that is, the first reflective portion 111 is not doped. Since the second reflection portion 112 has conductive properties, the doping concentration of the first reflection portion 111 is reduced, even if the first reflection portion 111 is made of an intrinsic material, the average doping concentration of the first mirror 110 can be effectively reduced, the absorption of the first reflection portion 111 on the light generated by the active region 120 can be effectively reduced, the loss of the resonant cavity can be effectively reduced, and the enhancement of the light emission intensity is facilitated.
In some embodiments of the present invention, the first reflective mirror 110 and the second reflective mirror 140 are Bragg reflectors (DBR), and the first reflective mirror 110 and the second reflective mirror 140 each include a high refractive index thin film and a low refractive index thin film, and the high refractive index thin film and the low refractive index thin film are alternately disposed. The adjacent high refractive index film and low refractive index film constitute one period. The reflectivity of the distributed bragg mirror is related to the periodicity of the high and low index films therein. For example, the first mirror 110 and the second mirror 140 may be Al alternately arranged in sequencexGa1-xAs/Al1-yGayAs thin film, wherein x and y can be different.
In order to guarantee the gain of the resonator, the first mirror 110 and the second mirror 140 must have a considerable number of cycles to meet the requirement of high reflectivity. And in order to ensure that the emitted laser light has a narrow line width, the light generated by the active region 120 forms a standing wave in the resonant cavity after being reflected by the first mirror 110 and the second mirror 140 for multiple times. Therefore, the first mirror 110 and the second mirror 140 need to have a relatively high reflectivity.
In this embodiment, the reflectivity of the first reflecting mirror 110 is greater than or equal to 99%, the number of cycles of the first reflecting mirror 110 is greater than or equal to 10, that is, the sum of the number of cycles of the first reflecting part 111 and the second reflecting part 112 is greater than or equal to 10, so as to meet the requirement of high reflectivity of the resonant cavity; the reflectivity of the second mirror 140 is greater than or equal to 99.9%, and the number of cycles of the second mirror 140 is greater than or equal to 25. The number of the whole periods of the first reflecting mirror 110 and the second reflecting mirror 140 is ensured, the first reflecting mirror 110 and the second reflecting mirror 140 can be ensured to meet the requirement of high reflectivity so as to form a resonant cavity, the gain of the resonant cavity can be ensured, and the luminous intensity can be ensured.
In this embodiment, the reflectivity of the second mirror 140 is higher than that of the first mirror 110, so that the direction of the second mirror 140 pointing to the first mirror 110 is the same as the laser emitting direction. The reflectivity of the second reflecting mirror 140 can reach more than 99.9%, so that the light energy loss caused by the transmission of the generated laser can be avoided as much as possible.
In some embodiments of the present invention, in the first reflecting mirror 110, the number of cycles of the first reflecting portion 111 is greater than or equal to the number of cycles of the second reflecting portion 112. The number of cycles of the second reflecting portion 112 with higher doping concentration is controlled, the average doping concentration of the first reflecting mirror 110 can be effectively controlled, the total doping amount can be effectively reduced, the conductive performance can be ensured, the absorption rate of light can be effectively reduced, the loss of the resonant cavity can be reduced, and the luminous intensity can be enhanced.
It should be noted that, if the number of cycles of the second reflective portion 112 is too low, the number of cycles of the first reflective portion 111 is too high, and the total doping amount of the first mirror 110 is too small, the overall resistance of the resonant cavity is increased, which affects the conductivity thereof; if the number of cycles of the second reflective portion 112 is too high, the number of cycles of the first reflective portion 111 is too low, and the total doping amount of the first reflective mirror 110 is too large, it is not favorable for reducing the absorption rate of light and controlling the cavity loss.
Therefore, in this embodiment, the ratio of the number of cycles of the second reflective portion 112 to the first reflective portion 111 is in the range of 1:1 to 1: 10. Specifically, the ratio of the number of cycles of the second reflection part 112 to the first reflection part 111 is in the range of 1:2 to 1: 5; the ratio of the number of cycles of the second reflection portion 112 to the number of cycles of the first reflection portion 111 is controlled, so that the local concentration of doped ions can be controlled to ensure the conductivity, the total amount of the doped ions can be reduced to reduce the loss, and the difficulty of the manufacturing process of the reflector can be reduced.
In this embodiment, the first doped ions in the second reflective portion 112 of the first reflective mirror 110 are N-type ions, and the doping concentration of the second reflective portion 112 is less than 2E18 atoms/cm3. In other embodiments of the present invention, the first doped ions in the second reflecting portion of the first mirror are P-type ions, and the second doped ions in the second reflecting portion of the first mirror are P-type ionsThe doping concentration of the reflective part 112 is less than 4E18 atom/cm3. Generally, the doping concentration of the N-type doped DBR is 2E 18-3E 18atom/cm3The doping concentration of the P-type doped distributed Bragg reflector is 4E18 atom/cm3Left and right. The doping concentration of the second reflective portion 112 is smaller, which can effectively reduce the absorption of light near the active region 120, and since the second reflective portion 112 is close to the active region 120, the current path is shorter, and the shorter current path can effectively control the resistance, so the smaller doping concentration of the second reflective portion 112 does not affect the conductivity. The second reflective portion 112 closer to the active region 120 has a smaller doping concentration, which can ensure the conductivity and reduce the light absorption.
It should be noted that in some embodiments of the present invention, in at least one of the second mirror 140 and the second reflective portion 112, the doping concentration of the material on the side close to the active region 120 is less than the doping concentration of the material on the side far from the active region 120. The closer to the active region 120, the higher the light density, so that the doping concentration of the material on the side close to the active region 120 is controlled, the conductivity can be ensured, and the doping concentration of the part of the reflector close to the active region is reduced, thereby reducing the light absorption rate of the reflector close to the active region, being beneficial to reducing the light intensity loss of the active region and enhancing the luminous intensity.
In this embodiment, the doping concentration of at least one of the second mirror 140 and the second reflective portion 112 is gradually decreased along the direction pointing to the active region 120. The gradual change of the doping concentration is realized, so that the light absorption rate can be reduced and the loss can be reduced; on the other hand, the process difficulty can be reduced, and the quality of the material film layer can be improved.
With continued reference to fig. 3, the active region 120 has a first surface (not labeled) and a second surface (not labeled) opposite to the first surface, and the direction of the second surface pointing to the first surface is consistent with the direction of the current flow; in some embodiments of the present invention, the resonant cavity further comprises: a current confinement layer on at least the second surface.
The current confinement layer is used to confine the current distribution range and suppress the current spreading effect, thereby increasing the current density of the light-emitting region in the active region 120 to improve the gain. In some embodiments of the invention, the current confinement layer comprises: the current limiting layer comprises conductive areas and insulating areas filled between the conductive areas, wherein the conductive areas penetrate through the current limiting layer along the current flowing direction.
In some embodiments of the present invention, the current confinement layer of the insulating region is made of an oxide; the material of the current confinement layer of the conductive region is a semiconductor compound. Specifically, the current confinement layer is formed by oxidizing a semiconductor compound, the oxidized semiconductor compound is used to form the insulating region, and the non-oxidized semiconductor compound is used to form the conductive region. The method for forming the current limiting layer by oxidizing the semiconductor compound can effectively ensure the surface flatness of the formed current limiting layer to obtain a flat interface on one hand, and can effectively reduce the internal stress of the formed current limiting layer to reduce the influence on light on the other hand. For example, in some embodiments, the material of the current confinement layer of the conductive region is aluminum gallium arsenide (Al)1-xGaxAs); the current confinement layer of the insulation region is made of aluminum oxide (Al)2O3) Or aluminum gallium oxide.
It should be noted that, as shown in fig. 3, in this embodiment, the current confinement layers are disposed on both sides of the active region 120, that is, the resonant cavity includes a first current confinement layer and a second current confinement layer, which are respectively located on the first surface and the second surface of the active region 120. However, the two current confinement layers are only provided as an example, and in other embodiments of the present invention, the resonant cavity may include only one current confinement layer.
It should be noted that, in the present embodiment, in order to simplify the process steps and improve the material quality, in the process of forming the current confinement layer, the semiconductor compound is oxidized after the growth of all the materials is completed, that is, in the embodiment shown in fig. 3, the semiconductor compound used for forming the current confinement layer is oxidized after the second mirror 140 is formed; only the semiconductor compound layer used to form the current confinement layer is shown in fig. 3. Specifically, the resonant cavity includes a first semiconductor compound 131 located at a first surface of the active region 120 and a second semiconductor compound 132 located at a second surface of the active region 120. However, this is merely an example, and in other embodiments of the present invention, the resonant cavity may be formed by a double epitaxy method, that is, after the semiconductor compound is formed, a machine is replaced to perform an oxidation step, which is not limited in the present invention.
Furthermore, in some embodiments of the present invention, a projection of the conductive region of the current confinement layer on the surface of the active region 120 is located at the geometric center of the active region 120. The conductive region is disposed at a position corresponding to the geometric center of the active region 120, so that the current can be localized in the central region of the active region 120, thereby increasing the current density of the light emitting region in the active region 120, which is beneficial to obtaining high gain. In this embodiment, the projection of the conductive region of the current confinement layer on the surface of the active region 120 is circular, and the current confinement layer has the function of increasing the current density, so that the conductive region is set to be circular to avoid the formation of a sharp corner shape, thereby effectively avoiding the problem of point discharge.
With continued reference to fig. 3, in some embodiments of the invention, the resonant cavity further comprises: a substrate 100, wherein the substrate 100 is located on a side of the first mirror 110 away from the active region 120, or the substrate 100 is located on a side of the second mirror 140 away from the active region 120.
The substrate 100 can provide a process platform during formation of the resonant cavity. In this embodiment, the mirror close to the substrate 100 is the first mirror 110, that is, as shown in fig. 3, the substrate 100 is located on a side of the first mirror 110 far from the active region 120. Therefore, in the process of forming the resonant cavity, the first mirror 110 including the first reflective portion 111 and the second reflective portion 112 is formed, and then the active region 120 and the second mirror 140 are sequentially formed on the first mirror 110. The process sequence can effectively reduce the process difficulty and is beneficial to obtaining high quality and high yield.
As described above, in the present embodiment, the direction in which the second mirror 140 points to the first mirror 110 coincides with the laser propagation direction. The generated light rays are emitted from the first reflector 110, so that the absorption of the emitted light rays can be reduced, the loss of the resonant cavity can be reduced, and the luminous intensity can be enhanced. And the substrate 100 is located on the side of the first mirror 110 away from the active region 120, so that the laser light generated by the resonant cavity exits from the substrate 100. In this embodiment, the resonant cavity is a resonant cavity of a back-side emitting laser.
In some embodiments of the present invention, the material of the substrate 100 is Semi-Insulator (SI) material or doped semiconductor material. In this embodiment, the substrate 100 is made of a semi-insulator material. By using a semi-insulator as a substrate, on one hand, the limitation of the substrate 100 on the conductivity types of the doped ions in the first reflecting mirror 110 and the second reflecting mirror 140 can be broken through, that is, when the substrate 100 is made of a semi-insulator material, the first doped ions in the second reflecting portion 112 of the first reflecting mirror 110 may be N-type ions or P-type ions, and the second doped ions in the second reflecting mirror 140 may be P-type ions or N-type ions, for example, when the first doped ions may be N-type ions, the second doped ions may be P-type ions; when the first doped ions are P-type ions, the second doped ions are N-type ions, so that the single flow direction of current is met; on the other hand, the semi-insulator material is not doped, so that the absorption of the substrate to light rays can be effectively reduced, and the loss of the resonant cavity is favorably reduced.
In other embodiments of the present invention, the material of the substrate may also be a doped semiconductor. The doped semiconductor may be one of N, P type doped GaAs, InP, GaSb, or InSb. When the material of the substrate is a doped semiconductor, the doped ions in the mirror close to the substrate in the first reflecting mirror and the second reflecting mirror are the same as the conductivity type of the doped ions in the substrate, that is, when the material of the substrate is an N-type doped semiconductor, the doped ions in the mirror close to the substrate are N-type ions, and the doped ions in the mirror far from the substrate are P-type ions; when the substrate is made of a P-type doped semiconductor, the doped ions in the reflector close to the substrate are P-type doped ions, and the doped ions in the reflector far away from the substrate are N-type ions, so that the single flow direction of current is ensured. The method of setting the type of the doped ions in the reflector close to the substrate to be consistent with the type of the doped ions in the substrate can improve the adaptability of the structure of the substrate and the structure of the reflector close to the substrate, thereby effectively improving the quality of the formed reflector.
It should be noted that, when the substrate is made of a doped semiconductor, in the resonant cavity of the back-side light emitting laser, the doped ions in the mirror close to the substrate are set as N-type doped ions with relatively low doping concentration, and correspondingly, the doped ions in the mirror far from the substrate are set as P-type doped ions.
It should be further noted that in other embodiments of the present invention, the resonant cavity may not include a substrate, that is, after the resonant cavity is completed, the substrate is removed to reduce the volume of the resonant cavity and avoid the loss of light through the substrate.
With continuing reference to fig. 3, in this embodiment, the resonant cavity further includes: a current conducting layer 150, the current conducting layer 150 being electrically connected with the second reflective portion 112. The current conducting layer 150 is located between the first reflection portion 111 and the second reflection portion 112, and enables connection of the second reflection portion 112 with an external circuit to form a current path of the resonant cavity.
In some embodiments of the present invention, the material of the current conducting layer 150 includes first doping ions, and the doping concentration of the current conducting layer 150 is greater than the doping concentration of the second reflecting portion 112. The current conducting layer150, the resistance can be effectively reduced and the conductivity can be improved by adopting higher doping concentration. In this embodiment, the doping concentration of the current conducting layer 150 can be 1E19 atom/cm3The above.
In some embodiments of the present invention, at least one of the first and second reflection parts 111 and 112 is made of a material different from that of the current conduction layer 150. Forming the current conduction Layer 150 using a material different from at least one of the first reflection part 111 and the second reflection part 112 enables the current conduction Layer 150 to function as an Etch Stop Layer (Etch Stop Layer) during formation. For example, the first reflector 110 and the second reflector 140 are Al alternately arranged in sequencexGa1-xAs/Al1-yGayWhen the As thin film (where x and y may have different values), the material of the current conducting layer 150 may be InGaP, so that the current conducting layer 150 and the first and second mirrors 110 and 140 may have a larger etching selectivity during etching.
As shown in fig. 3, in this embodiment, the first reflective portion 111 and the second reflective portion 112 are sequentially formed on the substrate 100, so that, in the process of forming the resonant cavity, etching is performed along a direction in which the second reflective portion 112 points to the first reflective portion 111, so that a material of the current conducting layer 150 is different from a material of the second reflective portion 112, and the current conducting layer serves as an etching stop layer in an etching process.
It should be noted that, in order to ensure that a standing wave is formed in the resonant cavity after the light is reflected by the first mirror 110 and the second mirror 140 for achieving the interference enhancement effect, the thickness of the current conducting layer 150 may be an integral multiple of the period of the first mirror 110 or the second mirror 140.
Referring to fig. 4, a schematic cross-sectional structure of another embodiment of the resonant cavity of the present invention is shown.
As shown in fig. 4, the resonant cavity includes: a first reflective part 211 of the first mirror, a current conducting layer 250, a second reflective part 212 of the first mirror, an active region 220, and a second mirror 240 on the substrate 200 in this order; a first current confinement layer 231 and a second current confinement layer 232 are disposed on the first surface and the second surface of the active region 220, respectively.
In this embodiment, the same points as those in the previous embodiments are not repeated herein. The difference from the previous embodiment is that, in this embodiment, the first reflecting mirror further includes: a third reflective part 213, the third reflective part 213 being positioned on a surface of the current conducting layer 250 facing the first reflective part 211, a material of the third reflective part 213 including first doping ions.
The third reflective portion 213 is used to ensure the electrical connection between the resonant cavity and an external circuit when over-etching occurs. In this embodiment, the third reflection unit is also a distributed bragg reflector, and the number of periods of the third reflection unit 213 is in the range of 1 to 2. Since the third reflective portion 213 has doped ions therein, the third reflective portion 213 also has an absorption effect on light, so that the period of the third reflective portion 213 is limited, and the absorption of light by the third reflective portion can be effectively controlled to reduce the loss of the resonant cavity.
In addition, in this embodiment, the doping concentration of the third reflective portion 213 is greater than the doping concentration of the second reflective portion 212. By setting the material of the third reflective portion 213 to be a material with a higher doping concentration, the conductivity of the third reflective portion 213 can be effectively improved, and the resistance of the resonant cavity can be reduced. Specifically, the doping concentration of the third reflective portion 213 may be 1E19 atom/cm3The above.
It can be seen that, when the third reflective portion 213 with high doping and few cycles is over-etched, the etching is stopped in the region of the third reflective portion 213, which not only improves the conductivity of the third reflective portion 213, but also controls the absorption of light by the third reflective portion 213, thereby achieving both high conductivity and low absorption rate.
It should be noted that, when the first mirror further includes the third reflection portion, in order to ensure the gain of the resonator, the first mirror still needs to have a considerable reflectivity, that is, the total number of cycles of the first mirror still needs to satisfy the requirement of high reflectivity, that is, the sum of the numbers of cycles of the first reflection portion 211, the second reflection portion 212 and the third reflection portion 213 still needs to satisfy the requirement of high reflectivity.
Referring to fig. 5, a schematic cross-sectional view of a resonant cavity according to yet another embodiment of the present invention is shown.
As shown in fig. 5, the resonant cavity includes: a first reflective part 311 of the first mirror, a current conducting layer 350, a second reflective part 312 of the first mirror, an active region 320, and a second mirror 340, which are sequentially located on the substrate 300.
The present embodiment is the same as the previous embodiments, and the description of the present invention is omitted. The difference from the previous embodiment is that, in the present embodiment, the active region 320 includes a plurality of active portions; the resonant cavity further comprises: a tunneling layer between adjacent active portions.
As shown in fig. 5, the active region 320 has a Multi-Junction (Multi-Junction) structure, and each active portion has a quantum well structure. A highly doped and small-thickness material layer is arranged between adjacent quantum well Junction surfaces to serve as a tunneling layer so as to form a Tunnel Junction (Tunnel Junction). The tunneling layer is connected to the adjacent active portions through quantum tunneling effect, so that quantum efficiency of the active region 320 is increased, and output optical power is improved.
Specifically, the active region 320 includes three active portions, which are a first active portion 321, a second active portion 322, and a third active portion 323, wherein a first tunneling layer 321b is disposed between the first active portion 321 and the second active portion 322, and a second tunneling layer 322b is disposed between the second active portion 322 and the third active portion 323.
Meanwhile, in order to reduce a Current Spreading effect (Current Spreading), in this embodiment, a Current confinement layer is further disposed on a surface into which a Current flows of each active portion, and the tunneling layer is located between the Current confinement layer and the active portion; alternatively, a current confinement layer is located between the tunneling layer and the active portion. The current limiting layer is arranged, so that the current can be concentrated to the center of each active part, the current density can be effectively improved, and high gain can be obtained.
In this embodiment, in the resonant cavity, the current flows along the direction in which the second mirror 340 points to the first mirror, so a first current confinement layer 321a is disposed between the first active portion 321 and the second active portion 322, a second current confinement layer 322a is disposed between the second active portion 322 and the third active portion 323, and a third current confinement layer 323a is disposed on the surface of the third active portion 323 facing the second mirror 340.
It should be noted that after the light is reflected by the first mirror and the second mirror 340 for multiple times, a standing wave is formed in the resonant cavity, the active portion is disposed at an anti-node position of the standing wave, and an electric field corresponding to the anti-node position is strongest, so that maximum amplification of the excited light can be obtained. The cavity further comprises a filling layer 321c to adjust the position of the interface between the material film layers in the cavity, especially the position of the active part at the antinode.
Correspondingly, the invention provides a method for forming a resonant cavity, which comprises the following steps: providing a substrate; forming a first mirror, an active region, and a second mirror on the substrate, wherein the first mirror and the second mirror are located at both sides of the active region in a laser propagation direction, wherein the first mirror includes: the reflective device comprises a first reflecting part and a second reflecting part positioned between the first reflecting part and the active region, wherein the material of the second reflecting part comprises first doping ions, the material of the second reflecting mirror comprises second doping ions, and the conductivity types of the first doping ions and the second doping ions are opposite.
Referring to fig. 6, a schematic cross-sectional structure diagram of an intermediate structure in an embodiment of the resonant cavity forming method is shown.
As shown in fig. 6, a substrate 400 is provided.
The substrate 400 provides a process platform during the formation of the resonant cavity.
In some embodiments of the present invention, the material of the substrate 400 is Semi-Insulator (SI) material or doped semiconductor material. In other embodiments of the present invention, the material of the substrate may also be a doped semiconductor. The doped semiconductor may be one of N, P type doped GaAs, InP, GaSb, or InSb. For specific technical features of the substrate, reference is made to the aforementioned embodiments of the resonant cavity, and the present invention is not described herein again.
After providing the substrate 400, a first mirror, an active region 420 and a second mirror 440 are formed on the substrate 400.
A gain medium capable of realizing population inversion is arranged in the active region 420, and a stimulated radiation amplification effect is generated; the first reflecting mirror is used for forming a reflecting surface of the resonant cavity; the second mirror 440 is used to form another reflecting surface of the resonant cavity; light generated by the active region 420 travels back and forth between the first mirror and the second mirror 440.
It should be noted that, for specific technical features of the first mirror, the active region 420 and the second mirror 440, reference is made to the aforementioned embodiments of the resonant cavity, and the description of the present invention is omitted herein.
In some embodiments of the present invention, the mirror near the substrate 400 is a first mirror (not labeled), and thus the steps of forming the first mirror, the active region 420 and the second mirror 440 include: the first mirror, the active region 420, and the second mirror 440 are sequentially formed on the substrate 400.
In this embodiment, the steps of forming the first mirror, the active region 420, and the second mirror 440 include: the first mirror, the active region 420, and the second mirror 440 are formed through an epitaxial growth process.
Since the second reflective part 412 of the first mirror and the second mirror 440 include doping ions, in-situ doping is performed during the epitaxial growth process for forming the first mirror, the active region 420, and the second mirror 440.
In the step of providing the substrate, when the material of the substrate is a doped semiconductor, the doping ions in the mirror of the first mirror and the second mirror close to the substrate have the same conductivity type as the doping ions in the substrate. By the method, the adaptability of the structure of the substrate and the structure of the reflector close to the substrate can be improved, so that the quality of the formed reflector can be effectively improved.
It should be noted that, when the material of the substrate is a doped semiconductor, in the resonant cavity of the back side emitting laser, preferably, the doping ions in the mirror close to the substrate are set as N-type doping ions with relatively low doping concentration, and the doping ions in the mirror far from the substrate are correspondingly set as P-type doping ions.
With continued reference to fig. 6, the active region 420 has a first surface (not labeled) and a second surface (not labeled) opposite to each other, the second surface pointing to the first surface in a direction consistent with the direction of current flow; in some embodiments of the present invention, the resonant cavity further comprises: a current confinement layer on at least the second surface.
In some embodiments of the invention, the current confinement layer comprises: the current limiting layer comprises conductive areas and insulating areas filled between the conductive areas, wherein the conductive areas penetrate through the current limiting layer along the current flowing direction. Wherein the current confinement layer of the insulating region is made of an oxide; the material of the current confinement layer of the conductive region is a semiconductor compound. Specifically, specific technical features of the current limiting layer refer to the embodiments of the resonant cavity, and the present invention is not repeated herein.
In some embodiments of the present invention, the current confinement layer is formed by oxidizing a semiconductor compound, the oxidized semiconductor compound forming the insulating region, and the non-oxidized semiconductor compound forming the conductive region. Specifically, the step of forming the current confinement layer includes: forming a semiconductor compound; oxidizing a semiconductor compound to form the current confinement layer.
In this embodiment, in order to simplify the process steps and improve the material quality, the semiconductor compound is oxidized after the growth of all the materials is completed in the process of forming the current confinement layer, that is, the semiconductor compound for forming the current confinement layer is oxidized after the second mirror 440 is formed.
Furthermore, in this embodiment, the current confinement layer is disposed on both the first surface and the second surface of the active region 420, and therefore, the step of forming the current confinement layer includes: forming a first semiconductor compound on the first mirror after forming the first mirror and before forming the active region 420, and forming a second semiconductor compound on the active region 420 after forming the active region 420 and before forming the second mirror 440; forming a second mirror 440 on the second semiconductor compound; after the second mirror 440 is formed, the first semiconductor compound and the second semiconductor compound are oxidized to form the first current confinement layer 431 and the second current confinement layer 432.
In other embodiments of the present invention, the semiconductor compound may be formed only on the first surface or only on the second surface, i.e., after the first mirror is formed and before the active region is formed; alternatively, a semiconductor compound is formed after the active region is formed and before the second mirror is formed.
It should be noted that, in other embodiments of the present invention, the resonant cavity may also be formed by a double epitaxy method, that is, after the semiconductor compound is formed, a machine is replaced to perform an oxidation step, which is not limited in the present invention.
With continued reference to fig. 6, in some embodiments of the present invention, a current conducting layer 450 is disposed between the first reflective portion 411 and the second reflective portion 412, so after forming the first reflective portion 411 and before forming the second reflective portion 412, the forming method further comprises: the current conducting layer 450 is formed on the first reflection portion 411.
The current conducting layer 450 is located between the first reflecting portion 411 and the second reflecting portion 412, and enables connection of the second reflecting portion 412 with an external circuit to form a current path of the resonant cavity. For specific technical features of the current conducting layer 450, reference is made to the aforementioned embodiments of the resonant cavity, and the detailed description of the present invention is omitted here.
In this embodiment, at least one of the first and second reflection parts 411 and 412 is made of a material different from that of the current conduction layer 450. Forming the current conducting Layer 450 using a material different from at least one of the first and second reflection parts 411 and 412 enables the current conducting Layer 450 to function as an Etch Stop Layer (Etch Stop Layer) during formation.
Specifically, as shown in fig. 6, the step of forming the first mirror, the active region 420 and the second mirror 440 includes: forming a first reflective material layer, an active material layer, and a second reflective material layer on the substrate 400; forming a cavity pattern layer on the stack of the first reflective material layer, the active material layer, and the second reflective material layer, the cavity pattern layer adapted to define the resonant cavity; and etching by taking the cavity pattern layer as a mask to form the resonant cavity.
In this embodiment, the material of the current conducting layer 450 is different from the material of the second reflecting portion 412. Therefore, the step of forming the resonant cavity by etching comprises the following steps: and etching by using the current conducting layer 450 as an etching stop layer.
In this embodiment, the direction of the second mirror 440 pointing to the first mirror coincides with the laser propagation direction. And the substrate 400 is located on the side of the first mirror away from the active region 420, so that the laser light generated by the resonant cavity exits from the substrate 400. In this embodiment, the resonant cavity is a resonant cavity of a back-side emitting laser.
As described above, in the present embodiment, after the second mirror 440 is formed, the semiconductor compound for forming the current confinement layer is oxidized, so as to simplify the process steps and improve the material quality. Specifically, after the resonant cavity is formed by etching, the side wall of the semiconductor compound for forming the current confinement layer is exposed; after exposing the semiconductor compound sidewalls, oxidation is performed.
It should be noted that, in the present embodiment, the substrate 400 is retained in the resonant cavity. In other embodiments of the present invention, the substrate may be removed from the resonant cavity to reduce the volume of the resonant cavity and avoid the loss of light transmitting the substrate. Specifically, in some embodiments of the present invention, after forming the resonant cavity, the forming method further includes: and removing the substrate.
It should be noted that, in the step of etching the resonant cavity, an Over etching (Over etch) may occur in the etching process, so that the etching step for forming the resonant cavity is stopped at the region outside the current conducting layer 450.
Referring to fig. 7, a schematic cross-sectional structure diagram of an intermediate structure in another embodiment of the resonant cavity forming method is shown.
The resonant cavity forming method comprises the following steps: providing a substrate 500; a first reflective portion 511 of the first mirror, a current conducting layer 550, a second reflective portion 512 of the first mirror, a first current confinement layer 531, an active region 520, a second current confinement layer 532, and a second mirror 540 are sequentially formed on the substrate 500.
The present embodiment is the same as the previous embodiments, and the present invention is not repeated herein, but the present embodiment is different from the previous embodiments, and in the present embodiment, the first reflecting mirror further includes: a third reflective part 513, the third reflective part 513 being located on a surface of the current conducting layer 550 facing the first reflective part 511, a material of the third reflective part 513 including first doped ions; in the step of forming the resonant cavity by etching, etching is performed in a direction in which the current conducting layer 550 is directed to the first reflecting portion 511.
Specifically, for specific technical features of the third reflecting portion 513, reference is made to the foregoing embodiments of the resonant cavity, and the description of the present invention is omitted here for brevity.
In the step of forming the resonant cavity by etching, when over-etching occurs, the etching step is stopped at the surface of the third reflecting part 513 or stopped in the third reflecting part 513. Therefore, even if the over-etching occurs, the third reflection part 513 can still ensure the electrical connection of the resonant cavity with an external circuit.
The invention also provides a laser unit, which specifically comprises: the resonant cavity is provided by the invention; a first electrode electrically connected to the resonant cavity; a second electrode electrically connected with the resonant cavity.
Referring to fig. 6, a schematic cross-sectional structure of an embodiment of the laser unit of the present invention is shown.
The laser unit includes: a resonant cavity, the resonant cavity being a resonant cavity of the present invention; a first electrode 461, the first electrode 461 being electrically connected with the resonant cavity; a second electrode 462, the second electrode 462 being electrically connected to the resonant cavity.
In this embodiment, the laser unit is a laser unit of a vertical cavity surface emitting laser.
The technical solution of the embodiment of the laser unit of the present invention is described in detail below with reference to the accompanying drawings.
The resonant cavity (not labeled in the figures) is the resonant cavity of the present invention.
The resonant cavity includes: a first reflective portion 411 of the first mirror, a current conducting layer 450, a second reflective portion 412 of the first mirror, a first current confinement layer 431, an active region 420, a second current confinement layer 432, and a second mirror 440, which are sequentially located on the substrate 400.
Specifically, the specific technical solution of the resonant cavity refers to the aforementioned embodiment of the resonant cavity, and the present invention is not described herein again.
As shown in fig. 6, in some embodiments of the present invention, the laser unit includes a core region 401 and an extension region 402 in a plane perpendicular to the propagation direction of the laser light; the resonant cavity is located within the core region 401; the current conducting layer 450 extends into the extension region 402.
In some embodiments of the present invention, during the process of forming the resonant cavity, the current conducting layer 450 is used as an etching stop layer for etching, that is, during the process of forming the resonant cavity, the etching step is stopped on the surface of the current conducting layer 450 or in the current conducting layer 450; thus, the thickness of the current conducting layer 450 of the extension region 402 is less than or equal to the thickness of the current conducting layer of the core region,
in this embodiment, the etching step is stopped in the current conducting layer 450, so that the thickness of the current conducting layer 450 of the extension region 402 is smaller than that of the current conducting layer 450 of the core region 401, and the surface of the current conducting layer 450 facing the active region 420 is stepped.
In other embodiments of the present invention, the etching step is stopped on the surface of the current conducting layer, so that the thickness of the current conducting layer in the extension region is equal to the thickness of the current conducting layer in the core region; the surface of the current conducting layer facing the active region is planar.
The first electrode 461 and the second electrode 462 respectively realize the connection of the resonant cavity and an external circuit so as to realize the power supply of the resonant cavity.
In some embodiments of the present invention, the first electrode and the second electrode are electrically connected to the resonant cavity by being electrically connected to the mirror, respectively. As shown in fig. 6, the first electrode 461 is electrically connected to the first mirror, and the second electrode 462 is electrically connected to the second mirror 440.
Therefore, in order to secure a single flow direction of current, the conductivity types of the first electrode and the second electrode need to be consistent with the conductivity type of the connected mirror. As shown in fig. 6, the first electrode 461 has the same conductivity type as the second reflective part 412 of the first mirror; the second electrode 462 has the same conductivity type as that of the second mirror 440, i.e., the first electrode 461 has the same conductivity type as that of the first doped ion, and the second electrode 462 has the same conductivity type as that of the second doped ion.
In this embodiment, the second reflective portion 412 of the first mirror is N-type doped, i.e. the first doped ions are N-type ions, so the first electrode 461 is an N-type electrode; the second mirror 440 is doped P-type, i.e., the second doped ions are P-type ions, so the second electrode 462 is a P-type electrode. The N-type electrode, the N-type doped mirror, the P-type doped mirror, and the P-type electrode are sequentially arranged on the substrate 400, and a current flows in a direction toward the substrate 400.
In other embodiments of the present invention, the second reflective portion of the first reflective mirror is P-type doped, that is, the first doped ions are P-type ions, so that the first electrode is a P-type electrode; the second mirror is N-type doped, i.e., the second doped ions are N-type ions, and thus the second electrode 462 is an N-type electrode. The P-type electrode, the P-type doped mirror, the N-type doped mirror, and the N-type electrode are sequentially arranged on the substrate, and the current flows in a direction away from the substrate.
In some embodiments of the present invention, the first electrode 461 is in contact with the current conducting layer 450 of the extension region 402, i.e. the first electrode 461 is electrically connected to the second reflecting portion 412 of the first mirror through the current conducting layer 450 of the extension region 402. It can be seen that the current conducting layer 450 extends in a plane parallel to the surface of the substrate 400, so that the transverse conduction of current can be realized, and the convenience of connecting the resonant cavity with external current can be improved.
In some embodiments of the present invention, the second electrode 462 is in contact with the second mirror 440, i.e., the second electrode 462 is directly electrically connected to the second mirror 440. As shown in fig. 6, the second electrode 462 is located on a side surface of the second mirror 440 away from the active region 420.
As shown in fig. 6, in this embodiment, the current conducting layer 450 of the first electrode 461 located in the extension region 461 faces the surface of the second mirror 440, i.e. the current conducting layer 450 of the first electrode 461 located in the extension region 461 faces the surface of the second electrode 462. Therefore, the first electrode 461 and the second electrode 462 face to the same side, so that the process difficulty of the subsequent contact layer arrangement can be reduced.
Referring to fig. 7, a schematic cross-sectional structure of another embodiment of the laser unit of the present invention is shown.
In the laser unit, the resonant cavity located in the core region 501 of the laser unit includes: a first reflective portion 511 of the first mirror, a current conducting layer 550, a second reflective portion 512 of the first mirror, a first current confinement layer 531, an active region 520, a second current confinement layer 532, a second mirror 540, and a second electrode 562, which are sequentially located on the substrate 500.
The present invention is not repeated herein where the present embodiment is the same as the previous embodiments. The present embodiment is different from the foregoing embodiments in that, in the present embodiment, the first reflecting mirror further includes: a third reflection part 513 between the current conduction layer 550 and the first reflection part 511.
In some embodiments of the present invention, when the resonant cavity is formed, in the process of etching by using the current conducting layer 550 as an etching stop layer, an Over etch (Over etch) may occur in the etching process, i.e., the etching step is stopped at the region outside the current conducting layer 550. The third reflecting portion 513 can still ensure the electrical connection between the resonant cavity and an external circuit when over-etching occurs.
In some embodiments of the present invention, as shown in fig. 7, the third reflective portion 513 extends to the extension region 502. When over-etching occurs, the current conducting layer 550 of the extension region 502 is removed, so the current conducting layer 550 is only located in the core region 501; but the current conducting layer 550 is in contact with the third reflecting portion 513, the third reflecting portion 513 of the extension region 502 enables the connection of the current conducting layer 550 with an external current, thereby achieving the electrical connection of the resonant cavity.
As shown in fig. 7, the first electrode 561 is in contact with the third reflection portion 513 of the extension region 502, that is, the first electrode 561 is connected to the current conduction layer 550 through the third reflection portion 513 of the extension region 502, and further connected to the second reflection portion 512.
Specifically, the first electrode 561 is located on a surface of the third reflective portion 513 of the extension region 502 facing the second mirror 540, that is, the first electrode 561 is located on a surface of the third reflective portion 513 of the extension region 502 facing the second electrode 562.
It should be noted that, since the etching process is over-etched when the resonant cavity is formed, the current conducting layer 550 of the extension region 502 is removed, and the etching step is stopped at the surface of the third reflective portion 513 or inside the third reflective portion 513, so that the thickness of the third reflective portion 513 of the extension region 502 is less than or equal to the thickness of the third reflective portion 513 of the core region 501. As shown in fig. 7, in this embodiment, the etching step is stopped at the surface of the third reflective portion 513, and the thickness of the third reflective portion 513 of the extension region 502 is equal to the thickness of the third reflective portion 513 of the core region 501, so that the surface of the third reflective portion 513 facing the first electrode 561 is a plane. In other embodiments of the present invention, the etching step is stopped inside the third reflective portion, and a thickness of the third reflective portion 513 of the extension region 502 is smaller than a thickness of the third reflective portion 513 of the core region 501, so that a surface of the third reflective portion facing the first electrode is stepped.
Correspondingly, the invention also provides a forming method of the laser unit, which specifically comprises the following steps: forming a resonant cavity, wherein the resonant cavity is formed by adopting the forming method of the invention; forming a first electrode electrically connected to the resonant cavity; forming a second electrode electrically connected to the resonant cavity.
Referring to fig. 6, a schematic cross-sectional structure diagram of an intermediate structure in an embodiment of the laser unit forming method is shown.
First, as shown in fig. 6, a resonant cavity is formed.
The resonant cavity is formed by the forming method of the invention. The specific technical features of the resonant cavity are described in the embodiments of the resonant cavity forming method, and the details of the present invention are not repeated herein.
After the resonant cavity is formed, a first electrode 461 and a second electrode 462 are formed.
In some embodiments of the present invention, the first electrode 461 is electrically connected to the second reflecting part 412 through the current conducting layer 450, and the second electrode 462 is electrically connected to the second reflecting mirror 440. As shown in fig. 6, in the present embodiment, a first electrode 461 is formed on the surface of the current conducting layer 450 of the extension 402 facing the second mirror 440, and a second electrode 462 is formed on the surface of the second mirror 440.
It should be noted that, for specific technical features of the first electrode 461 and the second electrode 462, reference is made to the foregoing embodiments of the laser unit, and the description of the present invention is omitted here for brevity.
Referring to fig. 7, a schematic cross-sectional structure diagram of an intermediate structure in another embodiment of the laser unit forming method is shown.
The present invention is not repeated herein where the present embodiment is the same as the previous embodiments. The present embodiment is different from the foregoing embodiments in that, in the present embodiment, the first reflecting mirror further includes: a third reflection part 513 between the current conduction layer 550 and the first reflection part 511.
In the step of forming the first electrode 561 and the second electrode 562, the first electrode 561 is formed on the surface of the third reflective part 513 of the extension region 502 facing the second mirror 540, and the second electrode 562 is formed on the surface of the second mirror 540.
It should be noted that, in this embodiment, the resonant cavity of the laser unit retains the substrate 500. In other embodiments of the present invention, particularly in back-emitting lasers, the substrate may also be removed to reduce the device size and reduce light transmission loss. Specifically, the substrate may be removed after the first electrode and the second electrode are formed.
The invention also provides a laser chip, which specifically comprises: one or more laser units, the laser units being the laser units of the invention; a first contact layer electrically connected to the first electrode; a second contact layer electrically connected with the second electrode.
Referring to fig. 8 and 9, schematic structural diagrams of an embodiment of a laser chip of the present invention are shown.
Fig. 8 is a schematic cross-sectional structure diagram of the embodiment of the laser chip, and fig. 9 is a schematic top-view structure diagram along the direction a in the embodiment of the laser chip shown in fig. 8.
As shown in fig. 8, the laser chip includes: one or more laser units, the laser units being the laser units of the invention; a first contact layer 671 electrically connected to the first electrode 661; a second contact layer 672, the second contact layer 672 being electrically connected to the second electrode 662.
In this embodiment, the laser chip is a laser chip of a vertical cavity surface emitting laser.
The technical solution of the embodiment of the laser chip according to the present invention is described in detail below with reference to the accompanying drawings.
The laser unit is the laser unit of the invention. Specifically, the specific technical solution of the laser unit refers to the foregoing embodiments of the laser unit, and the present invention is not described herein again.
The first contact layer 671 and the second contact layer 672 are electrically connected to the first electrode 661 and the second electrode 662, respectively, so as to electrically connect the laser unit to an external circuit.
In some embodiments of the present invention, in a plane perpendicular to the propagation direction of the laser light, the laser chip comprises a first region 601 and a second region 602 electrically isolated from the first region 601; the one or more laser units are located in the second region 602.
Specifically, the one or more laser units are effective laser units 620, that is, the laser units located in the second region 602 can be electrically connected to an external circuit, and can emit light when the external circuit is powered. In addition, in this embodiment, the laser chip further includes a dummy laser unit 610 located in the first region 601, where the dummy laser unit 610 cannot be electrically connected to an external circuit and cannot emit light.
As shown in fig. 9, the active laser units 620 are densely arranged in the second region 602, forming an array in the second region 602; the dummy laser units 610 are located within the first region 601. In this embodiment, only one dummy laser unit 601 is located in the first region 601.
In some embodiments of the present invention, the first contact layer 671 is located in the first region 601; the second contact layer 672 is located in the second region 602, and since the first region 601 and the second region 602 are electrically isolated, the first contact layer 671 and the second contact layer 672 are also electrically insulated from each other.
In some embodiments of the present invention, the first electrodes 661 of one or more of the laser units are connected; the first contact layer 671 is in electrical contact with the first electrode 661 through an interconnect structure (not labeled).
Specifically, the current conducting layer 650 of the one or more laser units is extended and connected; the first electrodes 661 of the laser units are located on the surface of the extended current conducting layer 650 so that the first electrodes 661 of different laser units are connected through the laterally extended current conducting layer 650; electrical connection between the first layer contact layer 671 and said current conducting layer 650 is achieved by means of a through-going interconnect structure.
In this embodiment, the plurality of laser units include: an edge laser unit (not shown) and a center laser unit (not shown), wherein the edge laser unit is located between the center laser unit and the first region 601; the interconnect structure is electrically connected to the first electrode 661 of the edge laser unit close to the first region 601. Since the current conducting layer 650 of the active laser unit 620 and the dummy laser unit 610 in the laser chip are extended, although the first contact layer 671 is connected to only the first electrode 661 of the edge laser unit near the first region 601, the first electrodes 661 of all laser units (whether the dummy laser unit 610 in the first region 601 or the active laser unit 620 in the second region 602) in the laser chip can be electrically connected to the first contact layer 671 through the laterally extended current conducting layer 650.
Note that, as shown in fig. 8, the first electrode is not disposed in the dummy laser unit 610; the first contact layer 671 and the dummy laser unit 610 are electrically isolated from each other by an insulating medium 603. In other embodiments of the present invention, the dummy laser unit may also be provided with the first electrode, but the bottom electrode does not serve an electrical role.
In some embodiments of the present invention, the directions of the second mirrors of the plurality of laser units pointing to the first mirror are all the same; the second contact layer 672 is in contact with the second electrodes 662 of the plurality of laser units. As shown in fig. 8, the second contact layer 672 is located on the surface of the second electrode 662 of the active laser unit 620 and contacts the second electrode 662 of the active laser unit 620 to realize electrical connection.
In other embodiments of the present invention (as shown in fig. 10), the second contact layer has a plurality of electrically isolated sub-contact layers 673, each sub-contact layer 673 is in contact with the second electrode 662 (as shown in fig. 8) of one or more active laser units 621, the sub-contact layers 673 may be in a plurality of stripe shapes (as shown in fig. 10) or in a plurality of rectangular shapes, and each sub-contact layer 673 is electrically connected to a driving circuit, so as to realize the address-selecting driving of the laser unit connected to the sub-contact layer 673.
It should be noted that, in the present embodiment, in the laser propagation direction, that is, on the straight line of the laser propagation direction, the first contact layer 671 and the second contact layer 672 are located on the same side of the laser chip, so that the laser chip is suitable for a flip chip process to avoid a metal wire bonding process, thereby avoiding an additional inductance effect and being beneficial to improving the response speed of the device; moreover, by disposing the first contact layer 671 and the second contact layer 672 on the same side of the laser chip, the first contact layer 671 and the second contact layer 672 can be formed in the same process, so as to reduce the number of process steps.
Specifically, as shown in fig. 8, the second contact layer 672 is located in the second region 602, and the second contact layer 672 is located on the surface of the second electrode 662 of the active laser unit 620 to realize electrical contact; the first contact layer 671, which is located at the same layer as the second contact layer 672, is electrically connected to the first electrode 661 on the surface of the current conducting layer 650 through an interconnection structure within the first region 601.
In addition, as shown in fig. 9, in the present embodiment, the first region 601 surrounds the second region 602. It should be noted that the arrangement manner of the first region 601 surrounding the second region 602 is only an example; in other embodiments of the present invention, the first region and the second region may be distributed in other manners, for example, the first region is located on both sides of the second region; or the first region and the second region are arranged at intervals, and the like.
Since the first contact layer 671 and the second contact layer 672 are located on the same side of the laser chip, after the laser chip is formed, in a subsequent assembly process, it is only necessary to electrically connect other circuit components such as a driver chip or a circuit board to the first contact layer 671 and the second contact layer 672 on the same side, flip-mount the laser chip on the driver chip or the circuit board, and solder the first contact layer 671 and the second contact layer 672 to electrical connection points on the chip or the circuit board on the same side.
Correspondingly, the invention also provides a method for forming the laser chip, which specifically comprises the following steps: forming one or more laser units, wherein the laser units are formed by adopting the forming method of the laser units; forming a first contact layer electrically connected to the first electrode; and forming a second contact layer electrically connected with the second electrode.
Referring to fig. 8 and 9 in combination, a schematic structural diagram of an intermediate structure in an embodiment of the laser chip forming method of the present invention is shown.
Fig. 8 is a schematic cross-sectional structure view of an intermediate structure in an embodiment of the laser chip forming method, and fig. 9 is a schematic top view structure view along the a direction in the intermediate structure in the embodiment of the laser chip shown in fig. 8.
First, as shown in fig. 8 and 9, one or more laser units are formed.
The laser unit is formed by the forming method of the invention. For specific technical features of forming the laser unit, reference is made to the foregoing embodiments of the laser unit forming method, and the present invention is not described herein again.
After the laser unit is formed, a first contact layer 671 and a second contact layer 672 are formed.
It should be noted that, for specific technical features of forming the first contact layer 671 and the second contact layer 672, reference is made to the foregoing embodiments of the laser chip, and details of the present invention are not repeated herein.
In some embodiments of the present invention, the first contact layer 671 and the second contact layer 672 are formed in the same process. Since the first contact layer 671 and the second contact layer 672 are located on the same side of the laser chip in the laser propagation direction, i.e., on a straight line in the laser propagation direction, forming the first contact layer 671 and the second contact layer 672 in the same process can reduce the number of process steps.
In addition, the present invention also provides a laser, specifically comprising: the laser chip is the laser chip of the invention.
Referring to fig. 11, a schematic structural diagram of an embodiment of the laser of the present invention is shown.
As shown in fig. 11, the laser includes: the laser chip 710 is provided, and the laser chip 710 is a laser chip of the invention.
In this embodiment, the laser is a vertical cavity surface emitting laser.
The technical solution of the embodiment of the laser according to the present invention is described in detail below with reference to the accompanying drawings.
The laser chip 710 is a laser chip of the present invention. Specifically, the specific technical solution of the laser chip 710 refers to the foregoing embodiments of the laser chip, and the present invention is not described herein again.
In this embodiment, the laser further includes: and the beam shaping element 720, wherein the beam shaping element 720 is positioned on the optical path of the laser generated by the laser chip 710. The beam shaping element 720 is capable of beam shaping the laser light generated by the laser chip 710. Particularly for the vertical cavity surface emitting laser, the divergence angle of the laser beam generated by the vertical cavity surface emitting laser is large, and the beam shaping element 720 can effectively improve the quality of the generated laser.
In some embodiments of the present invention, the laser chip 710 is a back-side emitting laser chip, that is, the light generated by the laser chip is emitted from the side of the substrate 700, that is, the laser chip 710 can emit light on the whole substrate 700, and therefore the beam shaping element 720 is located on the side of the substrate 700 away from the active region.
In some embodiments of the present invention, the substrate 700 of the laser chip 710 has a substantial thickness, for example, the thickness of the substrate 700 of the laser chip 710 may be in the range of 500 μm to 600 μm. Therefore, in this embodiment, the beam shaping element 720 and the substrate 700 are integrated, that is, a concave-convex structure with a desired shape is directly formed on the surface of the substrate 700 facing away from the active region to serve as the beam shaping element 720, so that the beam shaping element 720 is directly integrated on the laser chip 710, which is beneficial to improving the integration degree and reducing the size of the device.
In some embodiments of the present invention, the beam shaping element 720 is: at least one of a microlens array and a nanopillar structure array. In this embodiment, as shown in fig. 11, a surface of the substrate 700 facing away from the active region forms a structure of a nano-pillar array, so that different requirements of light beam convergence, collimation, divergence, and the like can be met on the laser chip 710.
It should be noted that, parameters such as the shape, size, surface curvature, and the like of micro-optical elements such as a micro-lens array or a nano-pillar array, which are used as beam shaping elements, are determined according to optical calculation, and a beam with a required collimation degree and a required divergence angle can be obtained after light emitted from the laser chip 710 passes through the micro-optical elements. When the laser device is as laser radar's light source, the produced laser of laser device need not to set up the block lens again in light path direction low reaches as laser radar's detecting light, improves transmitting system integrated level greatly, reduces laser radar's size.
However, the method of integrating the beam shaping element into the substrate of the laser chip is only an example, and in other embodiments of the present invention, the micro-optical element may not be fabricated on the substrate.
Specifically, referring to fig. 12, a schematic structural diagram of another embodiment of the laser of the present invention is shown.
The present embodiment is the same as the previous embodiments, and the description of the present invention is omitted. This embodiment differs from the previous embodiments in that the laser chip 810 is equipped with a separate optical shaping element 820 downstream in the optical path. Specifically, the optical shaping element 820 is a micro-lens array. The optical shaping element 820 and the laser chip 810 are connected by filling a light-transmitting material 830 therebetween.
It should be noted that, in the embodiment, the substrate of the laser chip 810 has been removed to avoid the absorption of light by the substrate, so as to reduce the optical energy loss and increase the light emission intensity.
Correspondingly, the invention also provides a manufacturing method of the laser, which specifically comprises the following steps: and forming a laser chip, wherein the laser chip is formed by adopting the forming method of the invention.
Referring to fig. 11, a schematic cross-sectional structure of an intermediate structure in an embodiment of the laser forming method is shown.
As shown in fig. 11, first, a laser chip 710 is formed.
The laser chip 710 is formed by the method for forming a laser chip of the present invention. Specific technical features of the laser chip are formed by referring to the embodiments of the laser chip forming method. The present invention will not be described herein.
In some embodiments of the present invention, after the laser chip 710 is formed, the method for forming the laser further includes: a beam shaping element 720 is disposed on the optical path of the laser light generated by the laser chip 710.
It should be noted that, for specific technical features of the beam shaping element 720, reference is made to the foregoing embodiments of the laser, and the description of the present invention is omitted here.
In some embodiments of the present invention, the laser chip 710 is a backside-emitting laser chip, that is, the light generated by the laser chip is emitted from one side of the substrate 700, that is, the laser chip 710 can emit light on the whole substrate 700; moreover, the substrate 700 of the laser chip 710 has a considerable thickness, for example, the thickness of the substrate 700 of the laser chip 710 can reach a range of 500 μm to 600 μm; thus, the beam shaping element 720 can be fabricated directly on the substrate 700 of the laser chip 710. Specifically, after the laser chip 710 manufacturing process is completed, the surface of the substrate 700 opposite to the active region may be directly etched to form a concave-convex structure, so as to form the beam shaping element 720 integrated with the substrate 700.
Referring to fig. 12, a schematic cross-sectional view of an intermediate structure in another embodiment of the laser forming method is shown.
The present embodiment is the same as the previous embodiments, and the description of the present invention is omitted. The present embodiment is different from the previous embodiments in that in the present embodiment, a separate optical shaping element 820 is disposed downstream of the optical path of the laser chip 810. Specifically, the optical shaping element 820 and the laser chip 810 are connected by filling a light-transmitting material 830 therebetween.
It should be noted that, in this embodiment, after the laser chip 820 is manufactured, the substrate is removed to prevent the substrate from absorbing light, so that the optical shaping element 820 is directly connected to the surface of the first reflecting mirror.
In addition, the invention also provides a laser radar, which specifically comprises: a light source comprising the laser of the present invention.
In the laser of the present invention, the resonant cavity is the resonant cavity of the present invention, and in the resonant cavity, the first mirror includes a first reflecting portion and a second reflecting portion, wherein the second reflecting portion has a first doped ion therein, and the second mirror has a second doped ion therein, so that the average doping concentration of the first reflecting portion is relatively small, and therefore, the absorption rate of light in the resonant cavity is low, the loss of the resonant cavity is small, and therefore, the light emitting intensity of the laser is large, that is, the light emitting intensity of the light source of the laser radar is large; the light source with larger luminous intensity can at least effectively prolong the detection distance of the laser radar.
In summary, in the resonant cavity of the present invention, the first mirror includes the first reflecting portion and the second reflecting portion, wherein the second reflecting portion has the first doping ion therein, and the second reflecting portion has the second doping ion therein, so that it is possible to reduce the average doping concentration of the first mirror, and it is possible to reduce the light absorption rate while ensuring the electrical conductivity, thereby being beneficial to both ensuring the electrical conductivity and reducing the loss of the resonant cavity, and being beneficial to enhancing the light emission intensity.
Especially, when the doping concentration of the second reflection portion is greater than that of the first reflection portion, even when the material of the first reflection portion may be an intrinsic material, that is, the material of the first reflection portion is not doped, so that the absorption rate of the first reflection portion to the excited light can be effectively reduced, and the second reflection portion closer to the active region can ensure high conductivity, thereby reducing light loss while ensuring high conductivity, and facilitating enhancement of light emission intensity.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.

Claims (30)

1. A resonant cavity, comprising:
an active region;
first and second mirrors located on both sides of the active region in a laser propagation direction, wherein the first mirror includes: a first reflective portion and a second reflective portion between the first reflective portion and the active region, the second reflective portion and the second mirror being of different doping types.
2. The resonator cavity of claim 1, wherein the doping concentration of the second reflective portion is greater than the doping concentration of the first reflective portion.
3. The resonant cavity of claim 1 or claim 2, wherein the material of the first reflective portion is intrinsic.
4. The resonant cavity of claim 1, wherein the first mirror and the second mirror are distributed bragg mirrors.
5. The resonator cavity according to claim 1 or 4, wherein the number of periods of the first reflective portion is greater than or equal to the number of periods of the second reflective portion.
6. The resonator cavity of claim 5, wherein a ratio of the number of periods of the second reflective portion to the first reflective portion is in a range of 1:2 to 1: 5.
7. The resonant cavity of claim 1, wherein the active region has first and second opposing surfaces, the second surface pointing in a direction of the first surface that is coincident with a direction of current flow;
the resonant cavity further comprises: a current confinement layer on at least the second surface.
8. The resonant cavity of claim 1, further comprising: a substrate located on a side of the first mirror away from the active region, or on a side of the second mirror away from the active region.
9. The resonant cavity of claim 1, wherein the direction of the second mirror toward the first mirror is coincident with the laser emission direction.
10. The resonant cavity of claim 8, wherein the substrate material is a semi-insulator material or a doped semiconductor material.
11. The resonant cavity of claim 1, wherein the active region comprises a plurality of quantum wells, or wherein the active region comprises a plurality of active portions;
the resonant cavity further comprises: a tunneling layer between adjacent active portions.
12. The resonant cavity of claim 1, further comprising: a current conducting layer electrically connected to the second reflective portion, the current conducting layer being of a different material than the second reflective portion.
13. The resonant cavity of claim 12, wherein the current conducting layer is between the first reflective portion and the second reflective portion.
14. The resonant cavity of claim 12, wherein the current conducting layer and the second reflective portion are of the same doping type, and wherein the doping concentration of the current conducting layer is greater than the doping concentration of the second reflective portion.
15. The resonant cavity of claim 12, wherein the first mirror further comprises: a third reflective part on a surface of the current conducting layer facing the first reflective part, the third reflective part having a same doping type as the second reflective part.
16. The resonator cavity of claim 15, wherein the doping concentration of the third reflective portion is greater than the doping concentration of the second reflective portion, or wherein the number of periods of the third reflective portion is in the range of 1 to 2.
17. A laser unit, comprising:
a resonant cavity according to any one of claims 1 to 16;
a first electrode electrically connected to the resonant cavity;
a second electrode electrically connected with the resonant cavity.
18. The laser unit of claim 17, wherein the laser unit comprises a core region and an extension region in a plane perpendicular to a direction of propagation of the laser light;
the resonant cavity is located in the core region, and the current conducting layer extends into the extension region;
the first electrode is in contact with the current conducting layer of the extension region.
19. The laser unit of claim 18, wherein a third reflective portion extends to the extension region, and the first electrode is in contact with the third reflective portion of the extension region.
20. A laser chip, comprising:
one or more laser units as claimed in any one of claims 17 to 19;
a first contact layer electrically connected to the first electrode;
a second contact layer electrically connected with the second electrode.
21. A laser, comprising:
a laser chip according to claim 20.
22. A lidar, comprising:
a light source comprising the laser of claim 21.
23. A method of forming a resonant cavity, comprising:
providing a substrate;
forming a first mirror, an active region, and a second mirror on the substrate, wherein the first mirror and the second mirror are located at both sides of the active region in a laser propagation direction, wherein the first mirror includes: a first reflective part and a second reflective part between the first reflective part and the active region, the second reflective part and the second mirror having different doping types.
24. The method of forming of claim 23, wherein the step of forming the first mirror, the active region, and the second mirror comprises: the first mirror, the active region, and the second mirror are sequentially formed on the substrate.
25. The method of forming as claimed in claim 23, wherein the first reflective portion and the second reflective portion have a current conducting layer therebetween;
the step of forming the first mirror, the active region, and the second mirror includes:
forming a first reflective material layer, an active material layer and a second reflective material layer on the substrate;
etching the stack of the first layer of reflective material, the layer of active material, and the layer of second reflective material to form the resonant cavity;
the step of forming the resonant cavity by etching comprises the following steps: and etching by taking the current conducting layer as an etching stop layer.
26. The method of forming as claimed in claim 25, wherein the first mirror further comprises: a third reflective part on a surface of the current conducting layer facing the first reflective part, the third reflective part having the same doping type as the second reflective part;
and in the step of forming the resonant cavity by etching, etching is carried out along the direction of the current conducting layer pointing to the first reflecting part.
27. A method of forming a laser unit, comprising:
forming a resonant cavity, wherein the resonant cavity is formed by the forming method according to any one of claims 23-26;
forming a first electrode electrically connected to the resonant cavity;
forming a second electrode electrically connected to the resonant cavity.
28. The method of forming as claimed in claim 27, further comprising:
after the first electrode and the second electrode are formed, the substrate is removed.
29. A method for forming a laser chip, comprising:
forming one or more laser units, the laser units being formed by the forming method according to any one of claims 27 to 28;
forming a first contact layer electrically connected to the first electrode;
and forming a second contact layer electrically connected with the second electrode.
30. A method of forming a laser, comprising:
forming a laser chip, the laser chip being formed by the forming method of claim 29.
CN202011351156.6A 2020-11-25 2020-11-25 Resonant cavity, laser unit, chip, laser, forming method and laser radar Pending CN114552380A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202011351156.6A CN114552380A (en) 2020-11-25 2020-11-25 Resonant cavity, laser unit, chip, laser, forming method and laser radar
PCT/CN2021/112715 WO2022110909A1 (en) 2020-11-25 2021-08-16 Resonant cavity, laser unit, chip, laser device and formation method therefor, and laser radar

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011351156.6A CN114552380A (en) 2020-11-25 2020-11-25 Resonant cavity, laser unit, chip, laser, forming method and laser radar

Publications (1)

Publication Number Publication Date
CN114552380A true CN114552380A (en) 2022-05-27

Family

ID=81668052

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011351156.6A Pending CN114552380A (en) 2020-11-25 2020-11-25 Resonant cavity, laser unit, chip, laser, forming method and laser radar

Country Status (2)

Country Link
CN (1) CN114552380A (en)
WO (1) WO2022110909A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115275783B (en) * 2022-09-26 2023-03-24 福建慧芯激光科技有限公司 Multi-wavelength VCSEL laser chip sharing DBR

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1901241A (en) * 2005-07-22 2007-01-24 安华高科技Ecbuip(新加坡)私人有限公司 Light emitting device and method of manufacturing the same
JP2007294787A (en) * 2006-04-27 2007-11-08 Ricoh Co Ltd Surface-emitting laser element, surface-emitting laser array, optical scanner, image forming apparatus, and optical communication system
CN101510665A (en) * 2008-02-13 2009-08-19 富士施乐株式会社 Laser, module, optical transmission device, optical transmission device and system
CN106575855A (en) * 2014-07-15 2017-04-19 华为技术有限公司 Vertical cavity surface emitting laser
CN109873296A (en) * 2019-01-29 2019-06-11 北京邮电大学 A kind of vertical cavity surface emitting laser chip and production method
CN110021875A (en) * 2018-01-09 2019-07-16 Lg 伊诺特有限公司 Surface emitting laser device and light emitting device including the same
CN111082316A (en) * 2020-01-17 2020-04-28 海南师范大学 Green light vertical cavity surface emitting semiconductor laser

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05152674A (en) * 1991-11-25 1993-06-18 Nec Corp Surface light emitting semiconductor laser with outer modulator
CN100479281C (en) * 2007-10-11 2009-04-15 北京工业大学 Double-capacitor micro-mechanical tunable vertical-cavity surface emitting laser and its manufacturing method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1901241A (en) * 2005-07-22 2007-01-24 安华高科技Ecbuip(新加坡)私人有限公司 Light emitting device and method of manufacturing the same
JP2007294787A (en) * 2006-04-27 2007-11-08 Ricoh Co Ltd Surface-emitting laser element, surface-emitting laser array, optical scanner, image forming apparatus, and optical communication system
CN101510665A (en) * 2008-02-13 2009-08-19 富士施乐株式会社 Laser, module, optical transmission device, optical transmission device and system
CN106575855A (en) * 2014-07-15 2017-04-19 华为技术有限公司 Vertical cavity surface emitting laser
CN110021875A (en) * 2018-01-09 2019-07-16 Lg 伊诺特有限公司 Surface emitting laser device and light emitting device including the same
CN109873296A (en) * 2019-01-29 2019-06-11 北京邮电大学 A kind of vertical cavity surface emitting laser chip and production method
CN111082316A (en) * 2020-01-17 2020-04-28 海南师范大学 Green light vertical cavity surface emitting semiconductor laser

Also Published As

Publication number Publication date
WO2022110909A1 (en) 2022-06-02

Similar Documents

Publication Publication Date Title
US6222866B1 (en) Surface emitting semiconductor laser, its producing method and surface emitting semiconductor laser array
JP4919639B2 (en) Surface emitting laser element, surface emitting laser array, surface emitting laser element manufacturing method, surface emitting laser module, electrophotographic system, optical communication system, and optical interconnection system
KR101409656B1 (en) Red light laser
US7778304B2 (en) Measuring arrangement and measuring system
US20050040410A1 (en) Tilted cavity semiconductor optoelectronic device and method of making same
US9014225B2 (en) Vertical cavity surface emitting laser device
KR102518449B1 (en) Indium Phosphide VCSEL with Dielectric DBR
EP3940902A1 (en) Vertical-cavity surface-emitting laser element
JP5254045B2 (en) Semiconductor laser device
US6621843B2 (en) Long wavelength surface-emitting semiconductor laser device and method for manufacturing the same
JP2857256B2 (en) Vertical semiconductor laser
JP7473271B2 (en) VCSEL laser device, chip and light source for LIDAR system with small divergence angle
US6717974B2 (en) Apparatus and method for improving electrical conduction structure of a vertical cavity surface emitting laser
JPH0555713A (en) Light emitting semiconductor element
WO2022110909A1 (en) Resonant cavity, laser unit, chip, laser device and formation method therefor, and laser radar
US20040125840A1 (en) Oxide-confined VCSEL device and the method for making the same
JPS63188983A (en) Semiconductor light emitting device
US20230231362A1 (en) Semiconductor laser with a horizontal laser element and a vertical laser element, lidar system and production method
JPH118406A (en) Surface-emitting element
KR20080052197A (en) Long wavelength vertical cavity surface emitting laser device and method for fabricating the same
KR20030033277A (en) Vertically integrated high-power surface-emitting laser diode and method of manufacturing the same
CN114649744A (en) Resonant cavity, laser unit, laser and laser radar
CN113612110A (en) VCSEL chip and manufacturing method thereof
WO2019107273A1 (en) Surface emission semiconductor laser
CN216162114U (en) Resonant cavity, laser unit, laser and laser radar

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination