CN112688170A - Array laser based on waveguide grating coupler and preparation method thereof - Google Patents
Array laser based on waveguide grating coupler and preparation method thereof Download PDFInfo
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- CN112688170A CN112688170A CN202011551878.6A CN202011551878A CN112688170A CN 112688170 A CN112688170 A CN 112688170A CN 202011551878 A CN202011551878 A CN 202011551878A CN 112688170 A CN112688170 A CN 112688170A
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Abstract
The invention provides an array laser based on a waveguide grating coupler and a preparation method thereof0.1Ga0.9As/Al0.9Ga0.1Lower DBR and quantum well active region Al alternately grown with As0.2Ga0.8Al0.12In0.18Ga0.7As, oxidation current limiting layer Al0.98/Ga0.02As、Al0.1Ga0.9As/Al0.9Ga0.1Upper DBR and SiO alternately grown with As2The device comprises a passivation layer, a P-type injection electrode Ti/Au, ultraviolet curing glue and a waveguide substrate; a vertically coupled waveguide; a lateral coupling waveguide layer; a two-dimensional diffraction grating. The overall spectral linewidth is reduced by the waveguide grating coupler. The preparation of the waveguide layer is realized without secondary epitaxy, the preparation cost is reduced, and the production yield is improved.
Description
Technical Field
The invention relates to the technical field of laser, in particular to an array laser based on a waveguide grating coupler and a preparation method thereof.
Background
With the increasing demand for the power of the laser light source, connecting multiple lasers in parallel to form an array laser is becoming a popular technical means for increasing the power of the lasers. However, since the array laser is configured by arranging a plurality of laser units that operate relatively independently to each other in a certain manner and then simultaneously operating as a whole to achieve higher output power, the independent operation of the plurality of units also brings a new problem for the array light source: the individual laser units in the array laser cannot be coherently coupled with each other due to the resonant cavity. This problem causes that each unit of the array laser may lase a plurality of laser beams with different wavelengths due to the heat dissipation environment and the process difference thereof, and such multi-wavelength lasing causes the problem that the spectral linewidth of the array laser is too wide, which is almost inevitable.
Because the coupling of a vertical cavity surface emitting laser (VCSEL for short) array is easy to realize due to the characteristic of planar two-dimensional arrangement, some researchers have proposed a technical scheme for optimizing the spectral line width of an array light source for the VCSEL array. The scheme is that the active regions of VCSEL array units are prepared to be very close to each other, and the active regions of a plurality of units are coupled with each other by using an evanescent wave or anti-waveguide method. However, the scheme is only suitable for small-scale low-power VCSEL arrays and is not suitable for large-scale high-power VCSEL arrays.
For an edge-emitting laser (EEL) array, the conventional method mainly comprises external cavity mode selection and reverse injection coupling, and a light path is required to be established by means of a complex and bulky external optical element for reverse injection, so that the method cannot meet the application with higher requirements on device cost and volume.
Disclosure of Invention
The invention provides an array laser based on a waveguide grating coupler and a preparation method thereof, which are used for overcoming the defects of high cost and large volume of devices in the prior art and realizing the array laser with low cost and small volume.
The invention provides an array laser based on a waveguide grating coupler, which sequentially comprises an N-type injection electrode Au/Ge/Ni/Au, an N-type GaAs substrate and Al from bottom to top0.1Ga0.9As/Al0.9Ga0.1Lower distributed Bragg reflector with As alternatively grown and Al0.2Ga0.8Al0.12In0.18Ga0.7As quantum well active region, Al0.98/Ga0.02As oxidation current limiting layer and Al0.1Ga0.9As/Al0.9Ga0.1As alternately-grown upper distributed Bragg reflector and SiO2The device comprises a passivation layer, a P-type Ti/Au injection electrode, ultraviolet curing glue and a waveguide substrate; a vertically coupled waveguide; a lateral coupling waveguide layer; a two-dimensional diffraction grating.
According to the array laser based on the waveguide grating coupler provided by the invention, a waveguide substrate is used as a carrier of a grating waveguide structure and is used as a low-refractive-index lower cladding layer of a transverse coupling waveguide layer, and a plurality of vertical coupling waveguides are arranged in the waveguide substrate. Each vertical coupling waveguide is positioned above the light outlet of each laser unit and is used for reversely coupling photons transmitted in the transverse coupling waveguide into the laser unit. The material of the vertically coupled waveguide must be consistent with the laterally coupled waveguide layer to improve the coupling efficiency of the coupler.
According to the waveguide grating coupler-based array laser provided by the invention, the vertical coupling waveguide is embedded in the waveguide substrate layer, and the size of the coverage area is matched with that of the light outlet of the laser unit, so that photons which are diffracted into the transverse coupling waveguide layer by the two-dimensional diffraction grating of the adjacent laser unit are longitudinally guided into the laser unit. The photons which are reversely coupled to the adjacent laser units can resonate in the resonant cavities of the adjacent laser units, and then a large number of photons with the same wavelength are generated through stimulated radiation, and finally the optimization of the spectral line width of the array laser is realized.
According to the waveguide grating coupler-based array laser provided by the invention, the transverse coupling waveguide layer is positioned on the upper surface of the waveguide substrate and covers the light outlets of all laser units and the positions between all adjacent diffraction gratings, so as to be used as a channel for transverse photon transmission, the thickness of the transverse coupling waveguide layer needs to be optimized according to the material used for preparation and the wavelength of a light source, and the length and the width need to be matched with the size of the light outlets of the laser units according to the distance between the laser units.
According to the waveguide grating coupler-based array laser provided by the invention, a two-dimensional diffraction grating is of a net structure prepared by periodic rectangular holes etched on the upper surface of a transverse coupling waveguide, the period and the duty ratio of the rectangular holes in two directions determine the period and the duty ratio of the grating, and the duty ratio and the period need to be subjected to targeted parameter optimization according to different wavelengths and different waveguide grating coupler materials so as to obtain higher coupling efficiency.
According to the waveguide grating coupler-based array laser provided by the invention, each two-dimensional diffraction grating is positioned above each vertical coupling waveguide, so that partial light beams transmitted through the grating are guided into the transverse coupling waveguide for transverse propagation through diffraction. And the area covered by the two-dimensional diffraction grating is matched with the area of the vertical coupling waveguide, so that the coupling efficiency of the whole coupler is improved.
The invention provides a preparation method of an array laser, which comprises the following steps:
etching a vertical coupling waveguide hole in the waveguide substrate layer by utilizing reactive ion etching;
growing Si on the surface of the quartz glass after etching the vertical coupling waveguide hole by utilizing Inductively Coupled Plasma Chemical Vapor Deposition (ICPCVD)3N4Filling the etched holes to form vertical coupling waveguides;
polishing the excessive Si on the surface of the quartz glass grown in the previous step3N4Exposing the quartz glass while planarizing the glass surface;
growing a layer of Si on the flat quartz glass again by ICPCVD3N4；
Etching the transverse waveguide grating coupling layer by utilizing a photoetching process;
etching a diffraction grating in the transverse waveguide grating coupling layer above the vertical waveguide grating coupling layer by using an electron beam exposure process;
the waveguide grating coupler is separated from the waveguide substrate plate using a laser cutting process.
The invention provides an assembly method of an array laser, which comprises the following steps:
adsorbing the array laser to a glass plate by using an electrostatic adsorption film, and adsorbing the glass plate to a wafer adsorption platform of a photoetching machine;
adsorbing the waveguide grating coupler to a glass plate by using an electrostatic adsorption film, and adsorbing the glass plate to a mask adsorption frame of a photoetching machine;
dripping proper ultraviolet curing glue on the surface of the array laser by using a micropipettor;
aligning a waveguide grating coupler and an array laser in a microscope of a photoetching machine, and aligning each laser unit to the center of a grating;
after the alignment is finished, the array laser and the waveguide grating coupler are tightly pushed and exposed, so that the glue is cured;
the glass plate is removed from the lithography machine, and then the waveguide grating coupler-equipped array laser is removed from the electrostatic adsorption film.
According to the waveguide grating coupler-based array laser and the preparation method thereof, the transverse coupling waveguide layer utilizes the waveguide to transversely transmit photons to realize coupling with a longer distance, so that the coupling is not limited by the distance of laser units, the waveguide grating coupler-based array laser is suitable for coupling of array lasers with various scales, and only different waveguide lengths need to be designed according to the scales of different array lasers.
The waveguide grating coupler is independently prepared from the array laser, has more excellent production yield and process applicability compared with the traditional scheme of preparing a reflecting or other types of coupling elements on the surface of the array laser by secondary epitaxy, has almost no influence on the whole volume of a device compared with external optical feedback type coupling, and has great advantages in cost.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a cross-sectional structure diagram of a 3 × 3 array-scale waveguide grating coupler-based high-power high-beam-quality VCSEL array laser of the present invention;
FIG. 2 is a schematic perspective view of a 3 × 3 array-scale high-power high-beam-quality VCSEL-based VCSEL array according to the present invention;
FIG. 3 is a schematic perspective view of a 3 × 3 array-scale two-dimensional waveguide grating coupler according to the present invention;
FIG. 4 is a schematic diagram of a cross-sectional structure of a 3 × 3 array-scale two-dimensional waveguide grating coupler based overall optical path and assembly structure according to the present invention;
FIGS. 5 to 11 are process flow diagrams of a 3 × 3 array-scale mesh two-dimensional waveguide grating coupler according to the present invention;
FIG. 12 is a flow chart of a method of making a waveguide grating coupler according to the present invention;
FIG. 13 is a flow chart of a method of assembling a waveguide grating coupler according to the present invention;
FIG. 14 is a graph of the pointinental vector intensity distribution along the transverse section of a transversely coupled waveguide calculated by simulation for a 3 × 3 array-scale waveguide grating coupler of the present invention that is mesh-shaped;
FIG. 15 is a diagram of a poynting vector intensity distribution of a longitudinal coupling waveguide transverse section along an electric field component direction obtained by simulation calculation for a 3 × 3 array-scale waveguide grating coupler of the present invention;
fig. 16 is a poynting vector intensity distribution diagram of a transverse section of a longitudinal coupling waveguide along a magnetic field component direction obtained by simulation calculation of the mesh-type 3 × 3 array-scale two-dimensional waveguide grating coupler according to the present invention.
Reference numerals:
1, N-type injection electrode; 2, N-type GaAs substrate;
3, a lower DBR; 4, quantum well active region;
5, oxidizing the current limiting layer; 6, upper DBR;
7，SiO2a passivation layer; 8, a P-type injection electrode;
9, ultraviolet curing glue; 10, a waveguide substrate;
11, a vertical coupling waveguide; 12, laterally coupling the waveguide layer;
13, diffraction grating.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The array laser based on the waveguide grating coupler provided by the embodiment of the invention realizes the mutual injection coupling of photons between adjacent laser units in the VCSEL array laser, improves the beam consistency by means of the injection phase locking technology, and finally achieves the purpose of reducing the array spectral line width, thereby solving the technical problems provided above.
The embodiment of the invention provides an array laser based on a waveguide grating coupler, and as shown in fig. 1 to 4, the structure of the array laser sequentially comprises an N-type injection electrode Au/Ge/Ni/Au1, an N-type GaAs substrate 2 and Al from bottom to top0.1Ga0.9As/Al0.9Ga0.1As grown alternatelyLower distributed Bragg reflector 3, Al0.2Ga0.8Al0.12In0.18Ga0.7As quantum well active region 4, Al0.98/Ga0.02As oxidation current limiting layer 5 and Al0.1Ga0.9As/Al0.9Ga0.1As alternately-grown upper distributed Bragg reflector 6 and SiO2The device comprises a passivation layer 7, a P-type Ti/Au injection electrode 8, ultraviolet curing glue 9, a waveguide substrate 10, a vertical coupling waveguide 11, a transverse coupling waveguide layer 12 and a two-dimensional diffraction grating 13.
A vertical coupling waveguide 11 embedded in the waveguide substrate, a lateral coupling waveguide layer 12 above the substrate layer, a two-dimensional diffraction grating 13 embedded in the lateral coupling waveguide layer.
The waveguide substrate 10 is used as the lower cladding of the optical waveguide structure, and the material can be SiO2Other materials that can form an effective waveguide structure with the waveguide core (i.e., the lateral coupling waveguide layer) are also possible. The layer also serves as a substrate for the entire waveguide grating structure, for carrying the entire two-dimensional waveguide grating structure.
The vertical coupling waveguide 11 embedded in the waveguide substrate 10 is located at the light exit of each laser unit in the array laser and is made of a material that must be compatible with the laterally coupled waveguide layer 12 for better coupling efficiency. The effect of this is to provide a window for each laser unit so that photons can be coupled from the vertically coupled waveguide into the cavity of an adjacent laser unit after lateral transmission.
The transverse coupling waveguide layer 11 is used as a core layer with high refractive index in the optical waveguide structure and can be made of Si3N4Other materials that can form an effective waveguide structure with the waveguide substrate 10 are also possible. In this configuration, the lateral coupling waveguide layer 12 serves as a bridge for coupling the individual laser units in the array laser, and serves to connect the two diffraction gratings for lateral transmission of photons.
A two-dimensional diffraction grating 13 is etched in the lateral coupling waveguide layer 12 in order to change the propagation direction of a portion of the light incident on the two-dimensional diffraction grating by diffraction so that it is coupled into the lateral coupling waveguide layer for lateral transmission.
The two-dimensional diffraction grating 13 is a mesh structure formed by mutually vertical strips, can be directly prepared in a transverse coupling waveguide layer by etching rectangular holes, and can respectively correspond to the directions of electric field and magnetic field components of incident light beams because the two-dimensional diffraction grating 13 respectively has a group of periods and duty ratios in two positive directions.
Then, two sets of parameters of the field components in the corresponding directions are optimized respectively, so that the two-dimensional diffraction grating 13 obtains higher diffraction efficiency in both directions, and more photons are guided into the waveguide.
It should be noted that: the waveguide substrate 10 serves both as a carrier for the entire two-dimensional waveguide grating coupler and as a lower cladding for the entire waveguide structure. May be quartz glass (SiO)2) Other materials capable of forming a waveguide structure with a laterally coupled waveguide layer are also possible. The thickness and size of the array laser are adjusted according to the scale of the array laser and the process conditions of the implementer.
On the basis of the above-described embodiments, it is preferable that the waveguide substrate 10 serves as a carrier of the grating structure and as a low-refractive-index lower cladding layer of the lateral coupling waveguide layer 12, and there are several vertical coupling waveguides 11 in the waveguide substrate 10, each of which is located above the light outlet of each laser unit.
On the basis of the above embodiment, it is preferable that the vertical coupling waveguide 11 is embedded in the waveguide substrate layer 10, the size of the coverage area is matched with the size of the light outlet of the laser unit, and the material must be consistent with the lateral coupling waveguide layer 12 to improve the coupling efficiency of the coupler.
The vertical coupling waveguide 11 is embedded in the waveguide substrate layer 10 as a key structure for lateral coupling and then reverse coupling. The cross section of the array laser can be cylindrical or other plane shapes, and the position of the array laser corresponds to the light outlet of each laser unit of the array laser. The size of the coverage area in the transverse direction is matched with the size of the light outlet of the laser unit. Either completely through the waveguide substrate 10 or embedded in the waveguide substrate 10 in a non-through manner. The material must be compatible with the laterally coupled waveguide layer 12 to maximize the coupling efficiency of the coupler.
On the basis of the above-mentioned embodiment, preferably, the lateral coupling waveguide layer 11 is located on the upper surface of the waveguide substrate 10, covering the light outlets of all the laser units, and all the positions between the adjacent two-dimensional diffraction gratings 13, in order to serve as a channel for lateral transmission of photons, the thickness of the lateral coupling waveguide layer needs to be optimized for the material used for preparation and the wavelength of the light source, and the length and width need to be matched according to the distance between the laser units and the size of the light outlets of the laser units.
The thickness of the laterally coupled waveguide layer 12, which is coated on the surface of the waveguide substrate 10, needs to be optimized specifically for the material and the scale of the array laser and the wavelength of the light source. The material may be Si3N4And may be another material capable of constituting a waveguide structure with the waveguide substrate 10. The entire array is connected in a laterally coupled waveguide layer 12 as a bridge connecting the individual laser elements, so that only the positions between the gratings (mutually perpendicular parts in fig. 2 and 3) need be covered, the Si in the remaining positions3N4Need to be removed to reduce the losses caused by unnecessary long-distance waveguide transmission.
On the basis of the above embodiment, preferably, the two-dimensional diffraction grating 13 is a mesh structure prepared by periodic rectangular holes etched on the upper surface of the transverse coupling waveguide layer 12, and the period and duty ratio of the rectangular holes in two directions determine the period and duty ratio of the grating, and the duty ratio and period need to be optimized according to the parameters of different wavelengths and different waveguide grating coupler materials, so as to obtain higher coupling efficiency.
The two-dimensional diffraction grating 13 is a key structure for realizing transverse coupling, and can guide part of photons of outgoing beams of N × M (N ≠ 1, M ≠ 1) laser units distributed in a two-dimensional plane in a laser array into a transverse coupling waveguide through diffraction so as to perform transverse propagation.
The embodiment of the invention provides a preparation method of a two-dimensional waveguide grating coupler, which comprises the following steps of:
110, etching a vertical coupling waveguide hole in the waveguide substrate layer by RIE (reactive ion etching);
120, growing Si on the surface of the quartz glass after etching the vertical coupling waveguide hole by ICPCVD3N4Filling the etched holes to form vertical coupling waveguide;
130, polishing the excessive Si on the surface of the quartz glass grown in the previous step by using a polishing process3N4The quartz glass is exposed and the surface of the glass can be planarized.
140, a layer of Si with precise and flat thickness is grown on the flat quartz glass by using the ICPCVD process again3N4As a lateral coupling waveguide layer;
150, etching out the transverse coupling waveguide by RIE;
an electron beam exposure process is used to etch a diffraction grating into the laterally coupled waveguide layer above each vertically coupled waveguide (i.e., at the laser exit port) 160.
And 170, separating the two-dimensional waveguide grating coupler from the waveguide substrate plate by using a laser cutting process.
The third aspect of the present disclosure provides an assembling method of a two-dimensional waveguide grating coupler for reverse coupling of an array laser, which is to implement a key support of the waveguide grating coupler independent of laser preparation, as shown in fig. 13, and includes the following steps:
210, adsorbing and fixing the array laser by using a glass plate with an electrostatic adsorption film, and adsorbing the glass plate on a wafer adsorption table of a photoetching machine;
220, adsorbing and fixing the two-dimensional waveguide grating coupler by using a glass plate attached with an electrostatic adsorption film, and adsorbing the glass plate to a mask adsorption frame of a photoetching machine;
230, smearing a proper amount of ultraviolet curing glue on the surface of the array laser by using a micropipette;
the two-dimensional waveguide grating coupler is aligned with the array laser in the microscope of the lithography machine, aligning each laser unit with each grating 240.
250, after the alignment is finished, the array laser and the two-dimensional waveguide grating coupler are properly jacked up and exposed, the glue is solidified, and the glass plate can be directly lifted after the glue is solidified. At this time, since the viscosity of the cured glue is greater than that of the electrostatic adsorption film, the grating is well retained on the surface of the device.
And 260, detaching the glass plate from the photoetching machine, and then removing the array laser assembled with the two-dimensional waveguide grating coupler from the electrostatic absorption film.
As can be seen from the above technical solutions and fig. 14 to 16, the two-dimensional waveguide grating coupler for coupling array laser units with each other and the manufacturing and assembling method thereof according to the present disclosure have at least one or some of the following advantages:
(1) the two-dimensional waveguide grating coupler and the structure provided by the disclosure realize mutual injection, and basically do not change the original volume of a device, compared with a scheme of realizing coupling by using an optical system, the two-dimensional waveguide grating coupler and the structure are more suitable for being applied to a use scene requiring a small volume of an array light source. And the size scale and the lasing wavelength of the array laser can be subjected to targeted adaptation optimization, and the coupling efficiency of the coupler is effectively improved.
(2) The unique waveguide scheme of the two-dimensional waveguide grating coupler can solve the problem of long-distance coupling of units of the high-power vertical cavity surface emitting array laser to a certain extent, reduce the spectral line width of the high-power array laser, and improve the time coherence of the light beam of the high-power array laser, thereby improving the light beam quality of the high-power array laser.
(3) Compared with the technical scheme of secondary epitaxial two-dimensional waveguide grating couplers on the array surface, the scheme is not easy to damage the prepared array laser.
(4) The assembling method of the two-dimensional waveguide grating coupler provided by the disclosure provides a feasible and accurate alignment assembling technical scheme for the grating waveguide coupler under the condition of not damaging the array laser and the two-dimensional waveguide grating coupler. The assembly scheme provides technical support for the preparation of the two-dimensional waveguide grating coupler independent of a device.
The two-dimensional waveguide grating coupler structure disclosed by the scheme has the advantages that the two-dimensional waveguide grating coupler structure can be prepared independently of a laser, and the structural parameters can be adjusted and optimized according to the scale, the lasing wavelength and the arrangement mode of the array laser.
For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.
Certain embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the disclosure are shown. Indeed, various embodiments of the disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.
An example of the present disclosure is a 3 x 3 scale 940nm wavelength Vertical Cavity Surface Emitting Laser (VCSEL) array based on a two-dimensional waveguide grating coupler.
The quartz glass substrate of the coupler used has a size of 15mm × 15mm × 0.2mm, and the surface thereof is first repeatedly cleaned with acetone and ethanol, and a plurality of two-dimensional waveguide grating couplers can be prepared on one glass substrate because of the large glass. In this example, 9 two-dimensional waveguide grating couplers were uniformly prepared on a glass substrate.
1. As shown in fig. 5, a vertical waveguide fill hole is etched: the holes are filled with a vertical coupling waveguide of 50um depth by 50um diameter etched using Reactive Ion Etching (RIE).
2. As shown in fig. 6, a vertically coupled waveguide is prepared: si growth using Inductively Coupled Plasma Chemical Vapor Deposition (ICPCVD) equipment3N4Filling the hole etched in the last step to form a vertical coupling waveguide, and because the Si with the thickness of 50um cannot be grown at one time3N4Therefore, it can be divided into a plurality of growths according to the process conditions.
3. As shown in FIG. 7, the excess Si is planarized3N4: removing redundant Si on the surface of quartz glass by using a sheet grinding machine3N4And the quartz glass surface is planarized to serve as a lower cladding for the laterally coupled waveguide.
4. As shown in fig. 8, a laterally coupled waveguide layer is prepared: growing Si 2.7um thick using Inductively Coupled Plasma Chemical Vapor Deposition (ICPCVD) process3N4And forming a transverse coupling waveguide layer.
5. As shown in fig. 9, the lateral coupling waveguide structure is etched: etching off unwanted Si in lateral coupling waveguide layer after photolithography3N4Material forming a laterally coupled waveguide.
6. As shown in fig. 10, a two-dimensional diffraction grating is etched: by electron beam exposure process on Si3N4Periodic rectangular holes are etched on the surface to form a two-dimensional diffraction grating. The periods of the two-dimensional grating in the X-axis direction and the Y-axis direction are 834nm and 559nm respectively, the duty ratio is 31.69% and 27.62%, and the hole depth is 866 nm.
7. As shown in fig. 11, a two-dimensional waveguide grating coupler was cut out of a glass substrate: and separating the prepared two-dimensional waveguide grating coupler from the glass substrate by using a laser cutting process, wherein the size of each two-dimensional waveguide grating coupler is 1mm multiplied by 0.203 mm.
8. Adsorbing and fixing the array laser by using a glass plate with an electrostatic adsorption film, adsorbing the glass plate on a wafer adsorption platform of a photoetching machine, and roughly placing the array laser in the center of a platform;
9. adsorbing and fixing the two-dimensional waveguide grating coupler by using a glass plate attached with an electrostatic adsorption film, adsorbing the glass plate on a mask adsorption frame of a photoetching machine, repeatedly verifying the relative positions of the device and the grating before fixing the adsorption frame, enabling the device and the grating to be overlapped and parallel to each other as much as possible, and reserving an adjustment space for later precision alignment;
10. coating a proper amount of ultraviolet curing glue on the surface of the array laser by using a micropipettor, and paying attention to the using amount of the glue to avoid that the glue covers too many electrodes too much to cause that pressure welding cannot be carried out;
11. the two-dimensional waveguide grating coupler is aligned with the array laser in a microscope of a lithography machine, and each laser unit is aligned with each grating. The angle alignment, the position alignment and the fine adjustment are carried out by a 20-time microscope, so that each grating is positioned at the midpoint of the light outlet of the laser. .
12. After the alignment is finished, the array laser and the two-dimensional waveguide grating coupler are properly tightly propped, and then are exposed for 1 minute, so that the glue is completely cured, and the electrostatic adsorption glass plate can be directly separated after the glue is cured. At this time, since the viscosity of the cured glue is greater than that of the electrostatic adsorption film, the grating is well retained on the surface of the device.
13. The electrostatic adsorption glass plate is detached from the photoetching machine, and then the vertical cavity surface emitting array laser assembled with the two-dimensional waveguide grating coupler is carefully taken down from the electrostatic adsorption film.
The embodiment of the invention provides a scheme for realizing surface emitting laser array beam coupling based on an independent two-dimensional coupling grating array, and the method does not need secondary epitaxy to realize the preparation of the waveguide layer, thereby greatly reducing the preparation cost and simultaneously greatly improving the production yield.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. A vertical cavity surface emitting array laser based on a two-dimensional waveguide grating coupler is characterized in that: the structure of the laser is sequentially provided with an N-type injection electrode Au/Ge/Ni/Au, an N-type GaAs substrate and Al from bottom to top0.1Ga0.9As/Al0.9Ga0.1Lower DBR and quantum well active region Al alternately grown with As0.2Ga0.8Al0.12In0.18Ga0.7As, oxidation currentConfinement layer Al0.98/Ga0.02As、Al0.1Ga0.9As/Al0.9Ga0.1Upper DBR and SiO alternately grown with As2The device comprises a passivation layer, a P-type injection electrode Ti/Au, ultraviolet curing glue and a waveguide substrate; a vertically coupled waveguide; a lateral coupling waveguide layer; a two-dimensional diffraction grating.
2. The VCSEL of claim 1, wherein: the waveguide substrate is used as a carrier of the grating structure and is used as a low-refractive-index lower cladding layer of the transverse coupling waveguide layer, a plurality of vertical coupling waveguides are arranged in the waveguide substrate, and each vertical coupling waveguide is positioned above the light outlet of each laser unit.
3. The VCSEL of claim 1, wherein: the vertical coupling waveguide is embedded in the waveguide substrate layer, the size of the coverage area is matched with the size of the light outlet of the laser unit, and the material must be consistent with the transverse coupling waveguide layer to improve the coupling efficiency of the coupler.
4. The VCSEL of claim 1, wherein: the transverse coupling waveguide layer is positioned on the upper surface of the waveguide substrate and covers the light outlets of all the laser units and the positions between all the adjacent diffraction gratings, the transverse coupling waveguide layer is used as a channel for transverse transmission of photons, the thickness of the transverse coupling waveguide layer needs to be optimized according to materials used for preparation and the wavelength of a light source, and the length and the width need to be matched with the size of the light outlets of the laser units according to the distance between the laser units.
5. The VCSEL of claim 1, wherein: the two-dimensional diffraction grating is a net structure prepared by periodic rectangular holes etched on the upper surface of the transverse coupling waveguide, the period and the duty ratio of the rectangular holes in two directions determine the period and the duty ratio of the grating, and the duty ratio and the period need to be subjected to targeted parameter optimization according to different wavelengths and different waveguide grating coupler materials so as to obtain higher coupling efficiency.
6. The VCSEL of claim 1, wherein: each two-dimensional diffraction grating is positioned above each vertically coupled waveguide and covers an area matching the area of the vertically coupled waveguide.
7. A method of manufacturing a waveguide grating coupler as claimed in any one of claims 1 to 6, comprising:
etching a vertical coupling waveguide hole in the waveguide substrate layer by utilizing reactive ion etching;
growing Si on the surface of the quartz glass after etching the vertical coupling waveguide hole by utilizing Inductively Coupled Plasma Chemical Vapor Deposition (ICPCVD)3N4Filling the etched holes to form vertical coupling waveguides;
polishing the excessive Si on the surface of the quartz glass grown in the previous step3N4Exposing the quartz glass while planarizing the glass surface;
growing a layer of Si on the flat quartz glass again by ICPCVD3N4；
Etching the transverse waveguide grating coupling layer by utilizing a photoetching process;
etching a diffraction grating in the transverse waveguide grating coupling layer above the vertical waveguide grating coupling layer by using an electron beam exposure process;
the waveguide grating coupler is separated from the waveguide substrate plate using a laser cutting process.
8. A method of assembling the array laser of any one of claims 1 to 6, comprising:
adsorbing the array laser to a glass plate by using an electrostatic adsorption film, and adsorbing the glass plate to a wafer adsorption platform of a photoetching machine;
adsorbing the waveguide grating coupler to a glass plate by using an electrostatic adsorption film, and adsorbing the glass plate to a mask adsorption frame of a photoetching machine;
dripping proper ultraviolet curing glue on the surface of the array laser by using a micropipettor;
aligning a waveguide grating coupler and an array laser in a microscope of a photoetching machine, and aligning each laser unit to the center of a grating;
after the alignment is finished, the array laser and the waveguide grating coupler are tightly pushed and exposed, so that the glue is cured;
the glass plate is removed from the lithography machine, and then the waveguide grating coupler-equipped array laser is removed from the electrostatic adsorption film.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020034205A1 (en) * | 2000-04-28 | 2002-03-21 | Evans Gary A. | High-power coherent arrays of vertical cavity surface-emitting semiconducting lasers |
| US6959027B1 (en) * | 2000-05-26 | 2005-10-25 | Opticomp Corporation | High-power coherent arrays of vertical cavity surface emitting lasers |
| CN104393485A (en) * | 2014-09-26 | 2015-03-04 | 中国科学院长春光学精密机械与物理研究所 | Laser array coherent device and preparation method thereof |
| CN105174209A (en) * | 2015-06-15 | 2015-12-23 | 中国科学院半导体研究所 | Wafer level photoetching machine bonding method |
-
2020
- 2020-12-24 CN CN202011551878.6A patent/CN112688170A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020034205A1 (en) * | 2000-04-28 | 2002-03-21 | Evans Gary A. | High-power coherent arrays of vertical cavity surface-emitting semiconducting lasers |
| US6959027B1 (en) * | 2000-05-26 | 2005-10-25 | Opticomp Corporation | High-power coherent arrays of vertical cavity surface emitting lasers |
| CN104393485A (en) * | 2014-09-26 | 2015-03-04 | 中国科学院长春光学精密机械与物理研究所 | Laser array coherent device and preparation method thereof |
| CN105174209A (en) * | 2015-06-15 | 2015-12-23 | 中国科学院半导体研究所 | Wafer level photoetching machine bonding method |
Non-Patent Citations (1)
| Title |
|---|
| LI HAO ET AL.: "Design and parameter optimization of two-dimensional waveguide coupler", 《PROCEEDINGS OF SPIE》 * |
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