WO2024048325A1 - Dispositif de source de lumière, dispositif de télémétrie et procédé de télémétrie - Google Patents

Dispositif de source de lumière, dispositif de télémétrie et procédé de télémétrie Download PDF

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Publication number
WO2024048325A1
WO2024048325A1 PCT/JP2023/029829 JP2023029829W WO2024048325A1 WO 2024048325 A1 WO2024048325 A1 WO 2024048325A1 JP 2023029829 W JP2023029829 W JP 2023029829W WO 2024048325 A1 WO2024048325 A1 WO 2024048325A1
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Prior art keywords
wavelength
light
reflective layer
light source
source device
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PCT/JP2023/029829
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English (en)
Japanese (ja)
Inventor
健二 田中
元 米澤
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ソニーグループ株式会社
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Publication of WO2024048325A1 publication Critical patent/WO2024048325A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C3/00—Measuring distances in line of sight; Optical rangefinders
    • G01C3/02—Details
    • G01C3/06—Use of electric means to obtain final indication
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/484—Transmitters
    • 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
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • 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
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/0941—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a laser diode
    • 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
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
    • H01S3/11—Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping
    • H01S3/1123—Q-switching
    • H01S3/113—Q-switching using intracavity saturable absorbers
    • 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
    • H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
    • H01S5/042—Electrical excitation ; Circuits therefor
    • 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
    • H01S5/14—External cavity lasers

Definitions

  • the present disclosure relates to a light source device, a distance measuring device, and a distance measuring method.
  • Laser technology is widely used in various fields such as microfabrication, medical care, and distance measurement.
  • short-pulse laser technology is expected to be applied to high-precision processing technology and highly efficient wavelength conversion technology.
  • a light source device using a Q switch is used in a wide range of application fields because it can obtain a high peak power exceeding kW (kilowatt) with a relatively simple configuration.
  • a light source device has been proposed in which the resonators for excitation light and oscillation light are overlapped to reduce the size and improve the peak power (see, for example, Patent Documents 1 and 2).
  • light source devices have been used as light sources for laser distance measuring devices LiDAR (Light Detection and Range). Since the high peak power of a light source device can increase the measuring distance, there is a demand for a light source device that can be miniaturized and has a high peak power.
  • LiDAR Light Detection and Range
  • the high peak power of the light source device can increase the distance measurement distance, making it possible to measure distances in further distant areas.
  • a high peak power may pose a problem in terms of laser safety.
  • the peak power can be easily changed by changing the driving method determined by the current value and injection time.
  • the peak power is determined by the Q value determined by the structure of the resonator and the characteristics of the laser medium and saturable absorption material used. Once decided, it was difficult to make it variable.
  • the present disclosure provides a light source device that can be downsized and has variable peak power using a passive Q switch of a solid-state laser.
  • a laminated semiconductor layer having an active layer that emits light of a first wavelength that changes depending on driving conditions; and a first reflective layer for the first wavelength; a second reflective layer for a second wavelength disposed on a first surface facing the light emitting surface of the laminated semiconductor layer; a third reflective layer for the first wavelength, disposed on a second surface disposed on the rear side of the optical axis from the first surface; a laser medium disposed between the second reflective layer and the third reflective layer; a fourth reflective layer for the second wavelength, which is disposed on the second surface or on the rear side of the optical axis from the second surface; a first resonator that causes light of the first wavelength to resonate between the first reflective layer and the third reflective layer; Equipped with The optical axis of the laminated semiconductor layer and the optical axis of the laser medium are arranged on one axis, A light source device is provided.
  • the driving conditions may include at least one of a driving current injected into the active layer or a temperature of the active layer.
  • the active layer emits one of at least two types of light having the first wavelength, each of which has a different wavelength, depending on the drive current,
  • the third reflective layer may have different reflectances for the at least two types of first wavelengths.
  • the active layer emits the longer light of the first wavelength as the drive current is larger,
  • the third reflective layer may have a higher reflectance as the first wavelength is longer.
  • the active layer emits the longer light of the first wavelength as the drive current is larger,
  • the third reflective layer may have a lower reflectance as the first wavelength is longer.
  • the first wavelength includes a third wavelength emitted when a first drive current is passed through the active layer, and a fourth wavelength emitted when a second drive current is passed through the active layer,
  • the third reflective layer may have different reflectances for the third wavelength and the fourth wavelength.
  • the third reflective layer has a higher reflectance for the fourth wavelength than a reflectance for the third wavelength,
  • the laser medium may not excite the second wavelength with respect to the third wavelength, and may excite the second wavelength with respect to the fourth wavelength.
  • the third reflective layer has a lower reflectance for the fourth wavelength than a reflectance for the third wavelength,
  • the laser medium may not excite the second wavelength with respect to the fourth wavelength, and may excite the second wavelength with respect to the third wavelength.
  • the third wavelength may be shorter than the fourth wavelength.
  • the laminated semiconductor layer has a plurality of first regions that each emit light of a different first wavelength
  • the third reflective layer may be provided corresponding to the plurality of first regions, and may have a plurality of second regions each having a different reflectance with respect to the first wavelength.
  • the laminated semiconductor layer has a plurality of first regions that emit light of the third wavelength or the fourth wavelength
  • the third reflective layer may be provided corresponding to the plurality of first regions, and may have a plurality of second regions having mutually different reflectances for the third wavelength and the fourth wavelength.
  • the laminated semiconductor layer may intermittently emit light of the first wavelength.
  • It may further include a second resonator that causes the light of the second wavelength to resonate between the second reflective layer and the fourth reflective layer.
  • the optical axis of the laminated semiconductor layer, the optical axis of the laser medium, and the optical axis of the saturable absorber may be arranged on one axis.
  • the light at the second wavelength may have a larger peak power than the light at the first wavelength.
  • the fourth reflective layer may emit Q-switched pulse wave light of the second wavelength.
  • a light source device that can emit light by switching wavelengths, A light receiving section, a distance measuring unit that measures the distance to the target object based on the light emission signal and the light reception signal of the light reception unit when the light emission signal of the light source device is reflected by the target object and received by the light reception unit; , comprising:
  • the light source device includes: a laminated semiconductor layer having an active layer that emits light of a first wavelength that changes depending on driving conditions; and a first reflective layer for the first wavelength; a second reflective layer for a second wavelength disposed on a first surface facing the light emitting surface of the laminated semiconductor layer; a third reflective layer for the first wavelength, disposed on a second surface disposed on the rear side of the optical axis from the first surface; a laser medium disposed between the second reflective layer and the third reflective layer; a fourth reflective layer for the second wavelength, which is disposed on the second surface or on the rear side of the optical axis from the second surface; a first resonator that causes light of
  • It may also include a drive unit that controls the drive conditions according to the distance to the target object.
  • the driving unit may switch and control the peak power of the light emission signal emitted from the light source device according to the distance to the target object.
  • the distance to the target object is measured based on the light emitting signal and the light receiving signal of the light receiving section.
  • the light source device includes: a laminated semiconductor layer having an active layer that emits light of a first wavelength that changes depending on driving conditions; and a first reflective layer for the first wavelength; a second reflective layer for a second wavelength disposed on a first surface facing the light emitting surface of the laminated semiconductor layer; a third reflective layer for the first wavelength, disposed on a second surface disposed on the rear side of the optical axis from the first surface; a laser medium disposed between the second reflective layer and the third reflective layer; a fourth reflective layer for the second wavelength, disposed on the second surface or disposed on the rear side of the optical axis from the second surface; a first resonator that causes light of the first wavelength to resonate between the first reflective layer and the third reflective layer; a second resonator that resonates light of the second wavelength between the second reflective layer and the fourth reflective layer,
  • the optical axis of the laminated semiconductor layer and the optical axis of the laser medium are arranged on one axis, A ranging method is provided.
  • FIG. 3 is a diagram showing how the first wavelength emitted by the active layer changes depending on the drive current.
  • FIG. 3 is a diagram showing how the first wavelength emitted by the active layer changes depending on the temperature.
  • FIG. 6 is a diagram showing how the reflectance of the third reflective layer changes depending on the first wavelength. This is a graph in which the section ⁇ a to ⁇ d is extracted from the graph in FIG. 4A. This is a graph in which the section ⁇ c to ⁇ f is extracted from the graph in FIG. 4A.
  • FIG. 7 is a diagram illustrating checkered pattern light emission of the light source device in the second embodiment.
  • FIG. 7 is a diagram showing light emission in a line and space pattern of a light source device in a second embodiment. It is a figure showing the pulse current given to the active layer in a 3rd embodiment. It is a figure showing the output of the 1st oscillation light L1 in a 3rd embodiment.
  • FIG. 3 is a diagram showing the output of second oscillation light L2.
  • FIG. 12 is a diagram illustrating a configuration example of a distance measuring device as an example of implementation of a light source device according to a fourth embodiment.
  • FIG. 6 is a diagram illustrating a laser beam emitting operation of a light source device when a subject is located at a short distance from a distance measuring device.
  • FIG. 6 is a diagram illustrating a laser beam emitting operation of a light source device when a subject is far away from a distance measuring device.
  • FIG. 1 is a block diagram showing an example of a schematic configuration of a vehicle control system.
  • FIG. 2 is an explanatory diagram showing an example of installation positions of an outside-vehicle information detection section and an imaging section.
  • FIG. 1 is a schematic diagram showing the configuration of a light source device 1 according to the first embodiment.
  • the light source device 1 is used, for example, as a medical laser or a light source for a distance measuring device, which will be described later.
  • the light source device 1 includes an excitation light source (laminated semiconductor layer) 2 and a laser medium 3. Further, the light source device 1 may include a saturable absorber 4.
  • the excitation light source 2 emits first oscillation light L1 for exciting the laser medium 3.
  • the excitation light source 2 is composed of semiconductor layers having a laminated structure in which a substrate 21, a fifth reflective layer R5, a cladding layer 22, an active layer 23, a cladding layer 24, and a first reflective layer R1 are laminated in this order.
  • the excitation light source 2 in FIG. 1 has a bottom emission type configuration in which the first continuous wave (CW) oscillation light L1 is emitted from the substrate 21, but the CW excitation light is emitted from the first reflective layer R1 side.
  • a top-emission type configuration is also possible.
  • the substrate 21 is, for example, an n-GaAs substrate. Since the n-GaAs substrate absorbs the first oscillation light L1, which is the excitation wavelength of the excitation light source 2, at a constant rate, it is desirable to make it as thin as possible in order to suppress absorption. On the other hand, it is desirable to have a thickness sufficient to maintain mechanical strength when joining, for example, to other members.
  • the active layer 23 performs surface emission of the first oscillation light L1.
  • the cladding layers 22 and 24 are, for example, AlGaAs cladding layers.
  • the first reflective layer R1 reflects the first oscillation light L1.
  • the fifth reflective layer R5 has a constant transmittance with respect to the first oscillation light L1.
  • a semiconductor distributed reflector (DBR) capable of electrical conduction is used.
  • DBR semiconductor distributed reflector
  • FIG. 2 is a cross-sectional view showing the support structure of the excitation light source 2 in the first embodiment.
  • the laser medium 3 shown in FIG. 1 is arranged on the substrate 21 in FIG. 2, and the saturable absorber 4 may be further arranged thereon.
  • the excitation light source 2 has an n-type contact layer 25 in addition to the stacked structure shown in FIG.
  • the contact layer 25 is laminated between the substrate 21 and the fifth reflective layer R5.
  • the contact layer 25 is electrically connected to the fifth reflective layer R5, the cladding layer 22, the active layer 23, the cladding layer 24, and the conductive layer 58 that covers the sidewalls of the first reflective layer R1.
  • the conductive layer 58 is an n-type metal layer, and insulating layers 59a and 59b are arranged around the conductive layer 58.
  • the support body 5 has a configuration in which a submount member 52 is arranged on a mount member 51. On the submount member 52, wiring layers 53a and 53b are arranged separately from each other. The wiring layer 53a is electrically connected to the conductive layer 57 stacked on the first reflective layer R1 via solder layers 56a and 56b. Conductive layer 57 is a p-type metal layer.
  • Pins 54a and 54b are attached to the mount member 51.
  • the pins 54a and 54b are arranged to penetrate the mount member 51 and are connected to a drive power source (not shown).
  • the pins 54a and 54b are connected to the wiring layers 53a and 53b by wires 55a and 55b, respectively.
  • the voltage applied to the pin 54a is applied to the first reflective layer R1 via the wire 55a, the wiring layer 53a, the solder layer 56a, and the conductive layer 57. Further, the voltage applied to the pin 54b is applied to the contact layer 25 via the wire 55b, the wiring layer 53b, the solder layer 56b, and the conductive layer 58.
  • a driving current is injected into the active layer 23 according to the potential difference between the voltage applied to the first reflective layer R1 and the voltage applied to the contact layer 25.
  • the wavelength of the first oscillation light L1 is referred to as a first wavelength ⁇ 1.
  • the first wavelength ⁇ 1 varies depending on the semiconductor material within the excitation light source 2.
  • the first wavelength ⁇ 1 also changes depending on driving conditions.
  • the driving conditions depend on, for example, the temperature of the active layer 23 or the above-mentioned driving current.
  • FIG. 3A is a diagram showing how the first wavelength ⁇ 1 emitted from the active layer 23 changes depending on the drive current.
  • the horizontal axis indicates the amount of drive current, and the vertical axis indicates the wavelength of the first oscillation light L1.
  • the active layer 23 emits the first oscillation light L1 having a longer wavelength as the driving current increases.
  • the third wavelength ⁇ 3 emitted when the first drive current I1 is applied and the fourth wavelength ⁇ 4 emitted when the second drive current I2 is applied are collectively referred to as the first wavelength ⁇ 1.
  • the first drive current I1 is assumed to be smaller than the second drive current I2.
  • the third wavelength ⁇ 3 is shorter than the fourth wavelength ⁇ 4.
  • FIG. 3B is a diagram showing how the first wavelength ⁇ 1 emitted from the active layer 23 changes depending on the temperature.
  • the horizontal axis represents the temperature of the active layer 23, and the vertical axis represents the wavelength.
  • the third wavelength ⁇ 3' emitted at the first temperature T1 and the fourth wavelength ⁇ 4' emitted at the second temperature T2 are collectively referred to as a first wavelength ⁇ 1.
  • the active layer 23 can switch and emit at least two types of first oscillation light L1, each having a different wavelength, by controlling the drive current or temperature.
  • the fifth reflective layer R5 is arranged on the substrate 21, for example.
  • the fifth reflective layer R5 has a multilayer reflective film made of Alz1Ga1-z1As/Alz2Ga1-z2As (0 ⁇ z1 ⁇ z2 ⁇ 1) doped with an n-type dopant (for example, silicon).
  • the fifth reflective layer R5 is also called n-DBR.
  • the active layer 23 has, for example, a multiple quantum well layer in which an Alx1Iny1Ga1-x1-y1As layer and an Alx3Iny3Ga1-x3-y3As layer are laminated.
  • the first reflective layer R1 has a multi-reflective film made of, for example, Alz3Ga1-z3As/Alz4Ga1-z4As (0 ⁇ z3 ⁇ z4 ⁇ 1) doped with a p-type dopant (for example, carbon).
  • the first reflective layer R1 is also called p-DBR.
  • Each semiconductor layer (fifth reflective layer R5, cladding layer 22, active layer 23, cladding layer 24, and first reflective layer R1) in the excitation light source 2 as an excitation light resonator is formed by MOCVD (Metal Organic Chemical Vapor Deposition: It can be formed using a crystal growth method such as metalorganic vapor phase epitaxy (MBE) or molecular beam epitaxy (MBE). After the crystal growth, processes such as mesa etching for element isolation, formation of an insulating film, and vapor deposition of an electrode film are performed to enable driving by injection of a driving current.
  • MOCVD Metal Organic Chemical Vapor Deposition: It can be formed using a crystal growth method such as metalorganic vapor phase epitaxy (MBE) or molecular beam epitaxy (MBE).
  • MBE metalorganic vapor phase epitaxy
  • MBE molecular beam epitaxy
  • the excitation light source 2 may be any member that emits excitation light that can excite the laser medium 3, and does not necessarily need to be a semiconductor laser element. Further, the material used for the excitation light source 2 may be a crystalline material or an amorphous material such as ceramic. Furthermore, the excitation light source 2 only needs to be able to make the first oscillation light L1 enter the laser medium 3, and does not need to include an optical system such as a lens.
  • a laser medium 3 is arranged on the opposite side of the substrate 21 of the excitation light source 2 from the fifth reflective layer R5, that is, on the rear side of the optical axis.
  • the laser medium 3 has a second reflective layer R2 and a third reflective layer R3.
  • the second reflective layer R2 is arranged on the first surface S1 facing the light exit surface of the excitation light source 2.
  • the third reflective layer R3 is arranged on the second surface S2 on the rear side of the optical axis than the first surface S1.
  • the laser medium 3 is arranged between the second reflective layer R2 and the third reflective layer R3.
  • the laser medium 3 emits the second oscillation light L2 when excited by the first oscillation light L1.
  • the laser medium 3 is arranged to face the saturable absorber 4.
  • the optical axis of the excitation light source 2 and the optical axis of the laser medium 3 are arranged on one axis.
  • the wavelength of the second oscillation light L2 is referred to as a second wavelength ⁇ 2 in this specification.
  • the laser medium 3 includes, for example, YAG (yttrium aluminum garnet) crystal Yb:YAG doped with Yb (yttribium).
  • the laser medium 3 is not limited to Yb:YAG, and examples of the laser medium 3 include Nd:YAG, Nd:YVO4, Nd:YLF, Nd:glass, Yb:YAG, Yb:YLF, Yb:FAP, Yb:SFAP. , Yb:YVO, Yb:glass, Yb:KYW, Yb:BCBF, Yb:YCOB, Yb:GdCOB, and Yb:YAB.
  • the laser medium 3 may be a four-level solid-state laser medium or a three-level solid-state laser medium. However, since the appropriate excitation wavelength differs depending on each crystal, it is necessary to select the material of the laser medium 3 according to the first wavelength ⁇ 1.
  • a reflective layer (for example, a dielectric multilayer film) that reflects excitation light may be provided on the surface of the laser medium 3 on the laser output side (third reflective layer R3).
  • the second reflective layer R2 disposed on the excitation light source 2 side is, for example, the first oscillation light L1 of the first wavelength ⁇ 1 emitted from the excitation light source 2. and reflects the second oscillation light L2 of the second wavelength ⁇ 2 emitted from the laser medium 3 with a predetermined reflectance.
  • the third reflective layer R3 provided on the opposite side of the excitation light source 2 transmits, for example, the second oscillation light L2 of the second wavelength ⁇ 2 emitted from the laser medium 3. Further, the third reflective layer R3 has different reflectances for at least two types of first oscillation light L1 having different wavelengths depending on the above-described drive current.
  • FIG. 4A is a diagram showing how the reflectance R of the third reflective layer R3 changes depending on the wavelength of the first oscillation light L1.
  • the horizontal axis indicates the wavelength of the first oscillation light L1
  • the vertical axis indicates the reflectance R of the third reflective layer R3.
  • the reflectance R is approximately 100% at maximum.
  • the wavelengths are assumed to increase in the order of wavelength ⁇ a ⁇ b ⁇ c ⁇ d ⁇ e ⁇ f.
  • the reflectance R is constant between wavelengths ⁇ a and ⁇ b.
  • the reflectance R increases at wavelengths ⁇ b to ⁇ c.
  • the reflectance R is constant between wavelengths ⁇ c to ⁇ d, and the reflectance R at this time is the maximum.
  • the reflectance R decreases at wavelengths ⁇ d to ⁇ e.
  • the reflectance R is constant from the wavelength ⁇ e to the wavelength f, and the reflectance R at this time is the lowest.
  • FIG. 4B is an enlarged view of the wavelength ⁇ a to ⁇ d section of the graph of FIG. 4A.
  • the third wavelength ⁇ 3 described above may be between the wavelengths ⁇ a and ⁇ b.
  • the fourth wavelength ⁇ 4 may be between the wavelengths ⁇ c to ⁇ d.
  • the third reflective layer R3 has a reflectance Ra for the third wavelength ⁇ 3.
  • it has a reflectance Rb higher than the reflectance Ra.
  • the reflectance Rb may be approximately 100%.
  • the third reflective layer R3 totally reflects the first oscillation light L1 at the fourth wavelength ⁇ 4.
  • the first oscillation light L1 has the third wavelength ⁇ 3, a certain amount of light is transmitted.
  • FIG. 4C is an enlarged view of the wavelength ⁇ c to ⁇ f section of the graph of FIG. 4A.
  • the third wavelength ⁇ 3 described above may be between wavelengths ⁇ c and ⁇ d.
  • the fourth wavelength ⁇ 4 may be between wavelengths ⁇ e and ⁇ f.
  • the third reflective layer R3 has a reflectance Rb for the third wavelength ⁇ 3.
  • the fourth wavelength ⁇ 4 it has a reflectance Rc lower than the reflectance Rb.
  • the third reflective layer R3 totally reflects the first oscillation light L1 having the third wavelength ⁇ 3.
  • the first oscillation light L1 having the fourth wavelength ⁇ 4 is transmitted to some extent.
  • a dielectric multilayer film in which layers made of a high refractive index material and layers made of a low refractive index material are alternately laminated is used.
  • the thickness of the dielectric multilayer film is, for example, one quarter of the wavelength of the first oscillation light L1, and the total number of layers is from several to several hundred layers.
  • High refractive index materials for the dielectric multilayer film include Al2O3, HfO2, TiO2, ZrO2, Ta2O5, Nb2O5, ZnO2, and materials with a refractive index of 1.6 to 2.5, and low refractive index materials include SiO2.
  • a material having a refractive index of 1.2 to 1.6 is used, such as , Al2O3, and MgF2.
  • a method for forming the dielectric multilayer film is, for example, a chemical vapor deposition (CVD) method, a reactive sputtering method, a RAS method (Radical Assisted Sputtering), a vacuum deposition method, or an ion-assisted deposition method. Further, such reflective films may be formed on both main surfaces of the optical filter.
  • the layer structure, material, and film-forming method of the second reflective layer R2 and the third reflective layer R3 are not limited to the above examples.
  • the excitation light source 2 and the laser medium 3 constitute a first resonator 11.
  • Three reflective layers (first reflective layer R1, fifth reflective layer R5, and third reflective layer R3) are provided inside the first resonator 11. Therefore, the first resonator 11 has a coupled cavity structure.
  • the light source device 1 in FIG. 1 may include a saturable absorber 4 arranged to face the third reflective layer R3 of the laser medium 3.
  • the saturable absorber 4 has a fourth reflective layer R4.
  • the optical axis of the saturable absorber 4 is aligned on one axis with the optical axis of the excitation light source 2 and the optical axis of the laser medium 3.
  • the saturable absorber 4 is made of, for example, Cr:YAG, and is a member that absorbs light of a predetermined wavelength and has the property that the light absorption rate decreases due to saturation of light absorption.
  • the saturable absorber 4 absorbs, for example, the second oscillation light L2 and transmits the first oscillation light L1.
  • the saturable absorber 4 functions as a passive Q switch for the second oscillation light L2. That is, the light source device 1 becomes a passive Q-switched pulse laser device when outputting light of the second wavelength ⁇ 2.
  • the second oscillation light L2 emitted from the laser medium 3 enters the saturable absorber 4, the second oscillation light L2 is absorbed, and as the degree of absorption increases, the saturable absorber 4 transmits the second oscillation light L2. rate is increasing. Thereafter, when the electron density of the excited level increases and the excited level is filled, the saturable absorber 4 becomes transparent, the Q value of the optical resonator increases, and laser oscillation occurs.
  • the fourth reflective layer R4 is a partial reflective layer that functions as an output coupler.
  • the fourth reflective layer R4 is arranged on the rear side of the optical axis than the second surface S2. Specifically, it is arranged along the light exit surface of the saturable absorber 4. Note that, as described above, there may be a light source device 1 that does not have the saturable absorber 4. When the light source device 1 does not have the saturable absorber 4, the fourth reflective layer R4 may be arranged on the second surface S2. In this case, the second oscillation light L2, which is a continuous wave, is emitted from the fourth reflective layer R4, but its peak power is smaller than that of the Q-switched light emitted from the saturable absorber 4.
  • the excitation light source 2, laser medium 3, and saturable absorber 4 in the light source device 1 may be joined together. Furthermore, a spacer, a polarization control element, a heat exhaust member, or the like may be arranged between the excitation light source 2 and the laser medium 3 or between the laser medium 3 and the saturable absorber 4.
  • a passive Q-switched pulse laser device is used, for example, as a light emitting device for a distance measuring device.
  • a passive Q-switched pulse laser device irradiates a target object with pulsed light, and a distance measuring device receives the light reflected from the object, thereby measuring the distance to the object.
  • the pulsed light emitted from the passive Q-switched pulse laser device is suitable for irradiating an object at a long distance.
  • the pulsed light emitted from the passive Q-switched pulse laser device is suitable for irradiating an object at a long distance.
  • a light source device 1 according to the present embodiment described below is characterized in that the peak power of the emitted laser light can be switched.
  • 5A and 5B are diagrams explaining the operation of the light source device 1 according to this embodiment.
  • a drive current into the active layer 23 through an unillustrated electrode of the excitation light source 2
  • surface emission of the first oscillation light L1 is performed from the active layer 23.
  • the first oscillation light L1 having the third wavelength ⁇ 3 between the wavelengths ⁇ a and ⁇ b shown in FIG. 4B can be emitted from the active layer 23.
  • the first oscillation light L1 is transmitted through the third reflective layer R3. Therefore, since the laser medium 3 cannot sufficiently absorb the first oscillation light L1, it cannot excite the second oscillation light L2.
  • FIG. 5A shows how the first oscillation light L1 passes through the third reflective layer R3 with a broken line.
  • the first resonator 11 causes the first oscillation light L1 to resonate between the first reflective layer R1 of the excitation light source 2 and the third reflective layer R3 of the laser medium 3, and the third reflective layer R3
  • the first oscillation light L1 is emitted from the first oscillation light L1.
  • the first oscillation light L1 that has passed through the third reflective layer R3 passes through the saturable absorber 4, and further passes through the fourth reflective layer R4, and is emitted from the light source device 1.
  • the laser medium 3 and the saturable absorber 4 do not perform a Q-switch operation.
  • the light source device 1 functions as a laser device that emits first oscillation light L1 consisting of a continuous wave.
  • the peak power can be made variable by, for example, PWM (Pulse Width Modulation) driving, which will be described later.
  • the first oscillation light L1 having the fourth wavelength ⁇ 4 between the wavelengths ⁇ c to ⁇ d in FIG. 4B can be emitted from the active layer 23.
  • the third reflective layer R3 reflects the first oscillation light L1 with a reflectance Rb.
  • the first resonator 11 confines the power of the first oscillation light L1 between the first reflective layer R1 and the third reflective layer R3. Thereby, since the laser medium 3 can sufficiently absorb the first oscillation light L1, the laser medium 3 is excited and the second oscillation light L2 of the second wavelength is generated. That is, the first oscillation light L1 functions as excitation light.
  • the first oscillation light L1 having the third wavelength ⁇ 3 between the wavelengths ⁇ c to ⁇ d in FIG. 4C is emitted from the active layer 23.
  • the first oscillation light L1 is reflected by the third reflective layer R3 with a reflectance Rb and is confined within the first resonator 11, so that the laser medium 3 excites the second oscillation light L2.
  • FIG. 5B shows how the first oscillation light L1 is reflected by the third reflective layer R3 with a broken line.
  • the laser medium 3 and the saturable absorber 4 constitute the second resonator 12. That is, the light source device 1 in FIG. 5B has a structure in which the first resonator 11 and the second resonator 12 are integrated. Further, the first resonator 11 and the second resonator 12 have a structure in which a member (in the example of FIG. 5B, the laser medium 3) is shared between the second reflective layer R2 and the third reflective layer R3.
  • the second oscillation light L2 is absorbed by the saturable absorber 4 in the second resonator 12, and the output surface of the saturable absorber 4 No light is emitted from the fourth reflective layer R4 on the side.
  • the second resonator 12 causes the second oscillation light L2 to resonate between the second reflective layer R2 of the laser medium 3 and the fourth reflective layer R4 of the saturable absorber 4, and from the reflective layer R4 side.
  • the second oscillation light L2 is emitted as a Q-switched pulse wave.
  • the second oscillation light L2 in FIG. 5B Since the second oscillation light L2 in FIG. 5B performs a passive Q-switch operation, it has a larger peak power than the first oscillation light L1 in FIG. 5A.
  • the active layer 23 can emit the first oscillation light L1 having the third wavelength ⁇ 3 and the fourth wavelength ⁇ 4, which are arbitrary wavelengths.
  • the third wavelength ⁇ 3 is within the wavelengths ⁇ a to ⁇ b in FIG.
  • the reflectance for the fourth wavelength ⁇ 4 becomes high.
  • the laser medium 3 does not excite the second oscillation light L2 with respect to the first oscillation light L1 with the third wavelength ⁇ 3, and excites the second oscillation light L2 with respect to the first oscillation light L1 with the fourth wavelength ⁇ 4.
  • the reflectance for the fourth wavelength ⁇ 4 becomes low.
  • the laser medium 3 does not excite the second oscillation light L2 with respect to the first oscillation light L1 with the fourth wavelength ⁇ 4, and excites the second oscillation light L2 with respect to the first oscillation light L1 with the third wavelength ⁇ 3. Excite L2.
  • the third wavelength ⁇ 3 is between the wavelengths ⁇ a and ⁇ b in FIG. A case in which the light source device 1 emits the first oscillation light L1 when the first drive current I1 is injected into the drive current I1, and the light source device 1 emits the second oscillation light L2 when the second drive current I2 is injected will be described.
  • the active layer 23 can emit at least two types of first oscillation light L1 having different wavelengths depending on the drive current.
  • the third reflective layer R3 has different reflectances for different wavelengths of the first oscillation light L1. Thereby, depending on the drive current injected into the active layer 23, it is possible to switch whether the first oscillation light L1 is transmitted through the third reflective layer R3 or reflected by the third reflective layer R3.
  • the laser medium 3 When the first oscillation light L1 has the third wavelength ⁇ 3, the laser medium 3 does not excite the second oscillation light L2, so the light source device 1 emits the first oscillation light L1 with a relatively low peak power.
  • the first oscillation light L1 has the fourth wavelength ⁇ 4, the laser medium 3 excites the second oscillation light L2, so the light source device 1 emits the second oscillation light L2 in the form of a Q-switched pulse wave.
  • the first oscillation light L1 or the second oscillation light L2 with different peak powers can be switched. Can be emitted.
  • the light source device 1 of the present disclosure for example, in order to control peak power, it can be realized with a simpler configuration than a configuration in which components such as an optical element are added externally, or a configuration in which a mechanical drive is added. be. Therefore, manufacturing costs can be reduced and miniaturization possible.
  • the light source device 1 according to the second embodiment is characterized by having an array-like structure.
  • FIG. 6 is a sectional view showing the configuration of the light source device 1 in the second embodiment.
  • the excitation light source 2 has a plurality of first regions A1 that emit the first oscillation light L1.
  • the third reflective layer R3 has a second area A2 corresponding to the first area A1.
  • the first region A1 is divided into a plurality of sub-regions, and the driving conditions for the active layer 23 differ depending on the sub-regions.
  • two adjacent sub-regions within the first region A1 emit the first oscillation light L1 having mutually different first wavelengths ⁇ 1.
  • the second area A2 is also divided into a plurality of sub-areas. Two adjacent sub-regions in the second region A2 have reflectances that correspond to the wavelength of the first oscillation light L1 emitted by the corresponding sub-regions in the first region A1.
  • the first region A1 includes a sub-region A11 that emits the first oscillation light L1 with the third wavelength ⁇ 3, and a sub-region A12 that emits the first oscillation light L1 with the fourth wavelength ⁇ 4.
  • the second area A2 includes a sub area A21 into which the first oscillation light L1 from the sub area A11 is incident, and a sub area A22 into which the first oscillation light L1 from the sub area A12 is incident.
  • the sub-region A21 within the second region A2 has a reflectance Ra for the third wavelength ⁇ 3. Furthermore, the sub-area A22 within the second area A2 has a reflectance Rb for the fourth wavelength ⁇ 4.
  • a first oscillation light L1 with a low peak power and a second oscillation light L2 with a high peak power are respectively emitted from the fourth reflective layer R4.
  • FIG. 7A is a diagram showing checkered pattern light emission of the light source device 1 in the second embodiment.
  • the first oscillation light L1 and second oscillation light L2 can be emitted in a checkerboard pattern, as shown in FIG. 7A.
  • FIG. 7B is a diagram showing light emission in a line and space pattern of the light source device 1 in the second embodiment.
  • the first oscillation light L1 and the second oscillation light L2 can be emitted in a line-and-space pattern, as shown in FIG. 7B.
  • a plurality of first reflected lights L1 having different peak powers can be emitted simultaneously from the light source device 1. Therefore, for example, short-distance distance measurement and long-distance distance measurement can be performed at the same timing.
  • the light source device 1 of the first embodiment emits the continuous wave first oscillation light L1 or the Q-switched pulse wave second oscillation light L2 by switching the drive current injected into the active layer 23. toggle between The first oscillation light L1 can be pulsed light similarly to the second oscillation light L2.
  • the first oscillation light L1 is made into pulsed light by making the drive current injected into the active layer 23 into a pulsed current.
  • the light source device 1 of the third embodiment can be used as a pulsed light source that can switch between the first wavelength ⁇ 1 and the second wavelength ⁇ 2.
  • the first drive current I1 injected into the active layer 23 is a pulse current.
  • FIG. 8A is a diagram showing a pulse current waveform injected into the active layer 23. The horizontal axis shows time, and the vertical axis shows the magnitude of drive current.
  • a first drive current I1 which is a pulse current, is injected into the active layer 23 at predetermined time intervals ⁇ t'. By performing PWM control on the pulse width and pulse interval of the pulse current, the peak power of the first oscillation light L1 having the third wavelength ⁇ 3 can be arbitrarily adjusted.
  • FIG. 8B is a waveform diagram of the first oscillation light L1 emitted from the light source device 1 in the third embodiment.
  • the horizontal axis shows time, and the vertical axis shows peak power.
  • the excitation light source 2 in the third embodiment outputs the first oscillation light L1 having the peak power P1 and the first wavelength ⁇ 1 at each time interval ⁇ t' described above. That is, thereby, the light source device 1 of the third embodiment outputs the first oscillation light L1 having the first wavelength ⁇ 1 as a pulse wave similar to the second oscillation light L2.
  • FIG. 8C is a waveform diagram of the second oscillation light L2 emitted from the light source device.
  • the horizontal axis shows time, and the vertical axis shows peak power.
  • the light source device 1 outputs the second oscillation light L2 having the peak power P2 at every time interval ⁇ t.
  • the pulse interval (time interval ⁇ t') of the first oscillation light L1 is determined by the pulse interval of the drive current injected into the active layer 23.
  • the pulse interval (time interval ⁇ t) of the second oscillation light L2 depends on the materials and thicknesses of the laser medium 3 and the saturable absorber 4, the reflectance of the first to fourth reflective layers R1 to R4, and the active layer 23. It is determined by the drive current injected into the
  • the second drive current I2 may also be applied as a pulse current similarly to FIG. 8A. Thereby, the pulse interval of the second oscillation light L2 can be controlled not only by the above conditions but also by the pulse interval of the second drive current I2.
  • the light source device 1 of the third embodiment can turn the first oscillation light L1 of the third wavelength ⁇ 3 into pulsed light with an arbitrary pulse interval. Therefore, the light source device 1 can switch and emit pulsed light having different wavelengths, and the pulsed light emitted from the light source device 1 can be used, for example, as a light emission signal for distance measurement.
  • the light source device 1 of the present disclosure can be applied to, for example, a distance measuring device.
  • FIG. 9 shows a configuration example of a distance measuring device 60 as an example of implementation of the light source device 1 according to the fourth embodiment.
  • the distance measuring device 60 includes a light emitting section 61, a driving section 62, a power supply circuit 63, a light emitting side optical system 64, a light receiving side optical system 65, a light receiving section 66, a signal processing section 67, a control section 68, and a temperature detecting section 69. ing.
  • the light emitting section 61 has a light source device 1 as a light source, and the light emitting section 61 may have a plurality of light source devices 1, or may be constituted by light source devices 1 arranged in a predetermined manner, such as a matrix. Good too.
  • the driving section 62 is configured to include a power supply circuit 63 for driving the light emitting section 61.
  • the power supply circuit 63 generates a power supply current for the drive unit 62 based on an input current from, for example, a battery (not shown) provided in the distance measuring device 60.
  • the drive section 62 supplies a drive current to the active layer 23 of the light source device 1 disposed within the light emitting section 61 based on the power supply current.
  • the driving section 62 takes in a light emission signal indicating light emission from the light source device 1 from the light emitting section 61.
  • the light emission signal is supplied to a distance measuring section (distance measuring section) 68a of the control section 68.
  • the light emission signal may be supplied directly to the distance measuring section 68a, or may be supplied to the distance measuring section 68a via the light receiving section 66.
  • the drive unit 62 may change the drive current supplied to the active layer 23 depending on the distance to the distance measurement target (subject S in FIG. 9).
  • the light emitted from the light emitting unit 61 is irradiated onto the subject (object) S as a distance measurement target via the light emitting side optical system 64. Then, the reflected light from the subject S of the light irradiated in this way enters the light receiving surface of the light receiving section 66 via the light receiving side optical system 65.
  • the light receiving section 66 is, for example, a light receiving element such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor, and receives reflected light from the subject S that enters through the light receiving side optical system 65 as described above. It receives light, converts it into an electrical signal, and outputs it.
  • a light receiving element such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor
  • the light receiving unit 66 performs, for example, CDS (Correlated Double Sampling) processing, AGC (Automatic Gain Control) processing, etc. on the electrical signal obtained by photoelectrically converting the received light, and further performs A/D (Analog/Digital) conversion. Perform processing. Then, the signal as digital data (light reception signal) is output to the subsequent signal processing section 67.
  • CDS Correlated Double Sampling
  • AGC Automatic Gain Control
  • the light receiving section 66 of this example outputs a frame synchronization signal Fs to the driving section 62. This allows the driving section 62 to cause the light source device 1 in the light emitting section 61 to emit light at a timing corresponding to the frame period of the light receiving section 66.
  • the signal processing unit 67 is configured as a signal processing processor using, for example, a DSP (Digital Signal Processor).
  • the signal processing section 67 performs various signal processing on the light reception signal input from the light receiving section 66.
  • the control unit 68 includes, for example, a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., or an information processing device such as a DSP, and controls the light emission by the light emission unit 61. It controls the driving section 62 for controlling the operation and controls the light receiving operation of the light receiving section 66.
  • a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc.
  • ROM Read Only Memory
  • RAM Random Access Memory
  • the control section 68 has a function as a distance measuring section 68a.
  • the distance measuring section 68a measures the distance to the subject S based on the light reception signal signal-processed by the signal processing section 67 and the light emission signal of the light source device 1 supplied from the driving section 62.
  • the distance measuring unit 68a of this example measures the distance of each part of the subject S to enable identification of the three-dimensional shape of the subject S.
  • the control unit 68 may notify the driving unit 62 of the distance to the subject S every time the distance measuring unit 68a measures the distance to the subject S.
  • the temperature detection section 69 detects the temperature of the light emitting section 61.
  • a configuration may be adopted in which temperature detection is performed using, for example, a diode.
  • information on the temperature detected by the temperature detection section 69 is supplied to the driving section 62, thereby enabling the driving section 62 to drive the light emitting section 61 based on the temperature information.
  • the distance measuring method in the distance measuring device 60 for example, a distance measuring method using an STL (Structured Light) method or a ToF (Time of Flight) method can be adopted.
  • STL Structured Light
  • ToF Time of Flight
  • the light receiving section 66 is, for example, an IR (Infrared) light receiving section using a global shutter method.
  • the distance measuring section 68a controls the driving section 62 so that the light emitting section 61 emits pattern light, and detects pattern distortion in the image signal obtained via the signal processing section 67. , calculate the distance based on how the pattern is distorted.
  • the ToF method measures the distance to the target object by detecting the flight time (time difference) of the light emitted from the light emitting unit 61 until it is reflected by the target object and reaches the light receiving unit 66. It is a method.
  • dToF direct ToF
  • SPAD Single Photon Avalanche Diode
  • the distance measuring section 68a calculates the time difference between light emission and light reception for the light emitted from the light emitting section 61 and received by the light receiving section 66 based on the signal inputted via the signal processing section 67, and calculates the time difference between light emission and light reception.
  • the distance to each part of the subject S is calculated based on the distance and the speed of light.
  • a light receiving portion capable of receiving IR light is used as the light receiving portion 66, for example.
  • the laser light emitted to the subject S may be switched depending on the distance to the subject S.
  • 10A and 10B are diagrams showing an example in which the light source device 1 in the distance measuring device 60 emits a laser beam to the subject S.
  • the control unit 68 notifies the driving unit 62 of the distance to the subject S every time the distance measuring unit 68a measures the distance to the subject S.
  • the peak power of the laser beam is low.
  • FIG. 10A is a diagram showing the laser beam emitting operation of the light source device 1 when the subject S is at a short distance from the distance measuring device 60.
  • the drive unit 62 injects the first drive current I1 into the active layer 23.
  • the active layer 23 emits the first oscillation light L1 having the third wavelength ⁇ 3. Since the first oscillation light L1 having the third wavelength ⁇ 3 is transmitted through the third reflective layer R3, the laser medium 3 does not excite the second oscillation light L2.
  • the light source device 1 emits the first oscillation light L1 with low peak power to the subject S.
  • the first oscillation light L1 irradiated onto the subject S is reflected by the subject S and received by the light receiving section 66, and short distance measurement is performed by the distance measuring section 68a.
  • the first reflected light L1 has a low peak power and does not reach far, so it is used for short distance measurement.
  • FIG. 10B is a diagram showing the laser beam emitting operation of the light source device 1 when the subject S is far away from the distance measuring device 60.
  • the drive unit 62 injects the second drive current I2 into the active layer 23.
  • the active layer 23 emits the first oscillation light L1 having the fourth wavelength ⁇ 4.
  • the excitation light L2 with the fourth wavelength ⁇ 4 is repeatedly reflected between the first reflective layer R1 and the third reflective layer R3, and a sufficient amount of the first reflected light L1 is absorbed by the laser medium 3. excites the second oscillation light L2.
  • the second oscillation light L2 is repeatedly reflected between the second reflection layer R2 and the fourth reflection layer R4, and when a sufficient amount of the second oscillation light L2 is absorbed by the saturable absorber 4, the light source device 1 emits the second oscillation light L2 with high peak power to the subject S.
  • the second oscillation light L2 is used for long distance measurement.
  • the drive unit 62 may switch the drive current injected into the active layer 23 based on the distance measurement result by the distance measurement device 60. Thereby, depending on the distance of the subject S, the light source device 1 can emit oscillated light with an optimal peak power.
  • the distance measuring device 60 of the fourth embodiment switches the emitted laser light according to the distance to the subject S using the light source device 1 of any of the first to third embodiments. be able to.
  • a laser beam with a higher peak power is emitted to a subject S at a far distance, and a laser beam with a lower peak power is emitted to a subject S at a close distance, taking laser safety into consideration. etc., laser light can be used depending on the situation.
  • the technology according to the present disclosure (this technology) can be applied to various products.
  • the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as a car, electric vehicle, hybrid electric vehicle, motorcycle, bicycle, personal mobility, airplane, drone, ship, robot, etc. It's okay.
  • FIG. 11 is a block diagram illustrating a schematic configuration example of a vehicle control system, which is an example of a mobile body control system to which the technology according to the present disclosure can be applied.
  • the vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001.
  • the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside vehicle information detection unit 12030, an inside vehicle information detection unit 12040, and an integrated control unit 12050.
  • a microcomputer 12051, an audio/image output section 12052, and an in-vehicle network I/F (interface) 12053 are illustrated.
  • the drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs.
  • the drive system control unit 12010 includes a drive force generation device such as an internal combustion engine or a drive motor that generates drive force for the vehicle, a drive force transmission mechanism that transmits the drive force to wheels, and a drive force transmission mechanism that controls the steering angle of the vehicle. It functions as a control device for a steering mechanism to adjust and a braking device to generate braking force for the vehicle.
  • the body system control unit 12020 controls the operations of various devices installed in the vehicle body according to various programs.
  • the body system control unit 12020 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as a headlamp, a back lamp, a brake lamp, a turn signal, or a fog lamp.
  • radio waves transmitted from a portable device that replaces a key or signals from various switches may be input to the body control unit 12020.
  • the body system control unit 12020 receives input of these radio waves or signals, and controls the door lock device, power window device, lamp, etc. of the vehicle.
  • the external information detection unit 12030 detects information external to the vehicle in which the vehicle control system 12000 is mounted.
  • an imaging section 12031 is connected to the outside-vehicle information detection unit 12030.
  • the vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image of the exterior of the vehicle, and receives the captured image.
  • the external information detection unit 12030 may perform object detection processing such as a person, car, obstacle, sign, or text on the road surface or distance detection processing based on the received image.
  • the imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of received light.
  • the imaging unit 12031 can output the electrical signal as an image or as distance measurement information.
  • the light received by the imaging unit 12031 may be visible light or non-visible light such as infrared rays.
  • the in-vehicle information detection unit 12040 detects in-vehicle information.
  • a driver condition detection section 12041 that detects the condition of the driver is connected to the in-vehicle information detection unit 12040.
  • the driver condition detection unit 12041 includes, for example, a camera that images the driver, and the in-vehicle information detection unit 12040 detects the degree of fatigue or concentration of the driver based on the detection information input from the driver condition detection unit 12041. It may be calculated, or it may be determined whether the driver is falling asleep.
  • the microcomputer 12051 calculates control target values for the driving force generation device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, Control commands can be output to 12010.
  • the microcomputer 12051 realizes ADAS (Advanced Driver Assistance System) functions, including vehicle collision avoidance or impact mitigation, following distance based on vehicle distance, vehicle speed maintenance, vehicle collision warning, vehicle lane departure warning, etc. It is possible to perform cooperative control for the purpose of ADAS (Advanced Driver Assistance System) functions, including vehicle collision avoidance or impact mitigation, following distance based on vehicle distance, vehicle speed maintenance, vehicle collision warning, vehicle lane departure warning, etc. It is possible to perform cooperative control for the purpose of
  • ADAS Advanced Driver Assistance System
  • the microcomputer 12051 controls the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040. It is possible to perform cooperative control for the purpose of autonomous driving, etc., which does not rely on operation.
  • the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030.
  • the microcomputer 12051 controls the headlamps according to the position of the preceding vehicle or oncoming vehicle detected by the vehicle exterior information detection unit 12030, and performs cooperative control for the purpose of preventing glare, such as switching from high beam to low beam. It can be carried out.
  • the audio and image output unit 12052 transmits an output signal of at least one of audio and images to an output device that can visually or audibly notify information to the occupants of the vehicle or to the outside of the vehicle.
  • an audio speaker 12061, a display section 12062, and an instrument panel 12063 are illustrated as output devices.
  • the display unit 12062 may include, for example, at least one of an on-board display and a head-up display.
  • FIG. 12 is a diagram showing an example of the installation position of the imaging section 12031.
  • the vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as the imaging unit 12031.
  • the imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle 12100.
  • An imaging unit 12101 provided in the front nose and an imaging unit 12105 provided above the windshield inside the vehicle mainly acquire images in front of the vehicle 12100.
  • Imaging units 12102 and 12103 provided in the side mirrors mainly capture images of the sides of the vehicle 12100.
  • An imaging unit 12104 provided in the rear bumper or back door mainly captures images of the rear of the vehicle 12100.
  • the images of the front acquired by the imaging units 12101 and 12105 are mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, and the like.
  • FIG. 12 shows an example of the imaging range of the imaging units 12101 to 12104.
  • An imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose
  • imaging ranges 12112 and 12113 indicate imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively
  • an imaging range 12114 shows the imaging range of the imaging unit 12101 provided on the front nose.
  • the imaging range of the imaging unit 12104 provided in the rear bumper or back door is shown. For example, by overlapping the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.
  • At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information.
  • at least one of the imaging units 12101 to 12104 may be a stereo camera including a plurality of image sensors, or may be an image sensor having pixels for phase difference detection.
  • the microcomputer 12051 determines the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the temporal change in this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. In particular, by determining the three-dimensional object that is closest to the vehicle 12100 on its path and that is traveling at a predetermined speed (for example, 0 km/h or more) in approximately the same direction as the vehicle 12100, it is possible to extract the three-dimensional object as the preceding vehicle. can.
  • a predetermined speed for example, 0 km/h or more
  • the microcomputer 12051 can set an inter-vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control), automatic acceleration control (including follow-up start control), and the like. In this way, it is possible to perform cooperative control for the purpose of autonomous driving, etc., in which the vehicle travels autonomously without depending on the driver's operation.
  • the microcomputer 12051 transfers three-dimensional object data to other three-dimensional objects such as two-wheeled vehicles, regular vehicles, large vehicles, pedestrians, and utility poles based on the distance information obtained from the imaging units 12101 to 12104. It can be classified and extracted and used for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the degree of risk of collision with each obstacle, and when the collision risk exceeds a set value and there is a possibility of a collision, the microcomputer 12051 transmits information via the audio speaker 12061 and the display unit 12062. By outputting a warning to the driver via the vehicle control unit 12010 and performing forced deceleration and avoidance steering via the drive system control unit 12010, driving support for collision avoidance can be provided.
  • the microcomputer 12051 determines a collision risk indicating the degree of risk of collision with each obstacle, and when the collision risk exceed
  • At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays.
  • the microcomputer 12051 can recognize a pedestrian by determining whether the pedestrian is present in the images captured by the imaging units 12101 to 12104.
  • pedestrian recognition involves, for example, a procedure for extracting feature points in images captured by the imaging units 12101 to 12104 as infrared cameras, and a pattern matching process is performed on a series of feature points indicating the outline of an object to determine whether it is a pedestrian or not.
  • the audio image output unit 12052 creates a rectangular outline for emphasis on the recognized pedestrian.
  • the display unit 12062 is controlled to display the .
  • the audio image output unit 12052 may control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.
  • the technology according to the present disclosure can be applied to, for example, the imaging unit 12031 among the configurations described above.
  • the light source device 1 according to the present disclosure may be provided together with the imaging section 12031.
  • the present technology can have the following configuration. (1) a laminated semiconductor layer having an active layer that emits light of a first wavelength that changes depending on driving conditions; and a first reflective layer for the first wavelength; a second reflective layer for a second wavelength disposed on a first surface facing the light emitting surface of the laminated semiconductor layer; a third reflective layer for the first wavelength, disposed on a second surface disposed on the rear side of the optical axis from the first surface; a laser medium disposed between the second reflective layer and the third reflective layer; and a laser medium disposed on the second surface or on the rear side of the optical axis from the second surface.
  • the driving condition includes at least one of a driving current injected into the active layer or a temperature of the active layer.
  • the light source device according to (1) the active layer emits light of at least two types of the first wavelength, each having a different wavelength, depending on the drive current;
  • the third reflective layer has different reflectances for the at least two types of first wavelengths, The light source device according to (2).
  • the active layer emits the longer light of the first wavelength as the drive current is larger;
  • the third reflective layer has a higher reflectance as the first wavelength is longer.
  • the active layer emits the longer light of the first wavelength as the drive current is larger;
  • the third reflective layer has a lower reflectance as the first wavelength is longer.
  • the first wavelength includes a third wavelength emitted when the first drive current is passed through the active layer, and a fourth wavelength emitted when the second drive current is passed through the active layer.
  • the third reflective layer has different reflectances for the third wavelength and the fourth wavelength, The light source device according to (2) or (3).
  • the third reflective layer has a higher reflectance for the fourth wavelength than for the third wavelength; The laser medium does not excite the second wavelength with respect to the third wavelength, and excites the second wavelength with respect to the fourth wavelength.
  • the third reflective layer has a lower reflectance for the fourth wavelength than for the third wavelength; The laser medium does not excite the second wavelength with respect to the fourth wavelength, and excites the second wavelength with respect to the third wavelength.
  • the laminated semiconductor layer has a plurality of first regions that each emit light of a different first wavelength
  • the third reflective layer is provided corresponding to the plurality of first regions, and has a plurality of second regions each having a different reflectance with respect to the first wavelength.
  • the light source device according to any one of (1) to (9).
  • the laminated semiconductor layer has a plurality of first regions that emit light of the third wavelength or the fourth wavelength
  • the third reflective layer is provided corresponding to the plurality of first regions, and has a plurality of second regions having mutually different reflectances with respect to the third wavelength and the fourth wavelength.
  • (12) the laminated semiconductor layer intermittently emits light of the first wavelength;
  • the light source device according to any one of (1) to (9).
  • the light source device according to any one of (1) to (12).
  • (14) further comprising a saturable absorber having the fourth reflective layer, The optical axis of the laminated semiconductor layer, the optical axis of the laser medium, and the optical axis of the saturable absorber are arranged on one axis, The light source device according to any one of (1) to (13).
  • the light at the second wavelength has a larger peak power than the light at the first wavelength.
  • the light source device according to (14).
  • the fourth reflective layer emits Q-switched pulsed wave light of the second wavelength; The light source device according to (14) or (15).
  • a light source device capable of emitting light by switching the wavelength;
  • a light receiving section a distance measuring unit that measures the distance to the target object based on the light emission signal and the light reception signal of the light reception unit when the light emission signal of the light source device is reflected by the target object and received by the light reception unit;
  • the light source device includes: a laminated semiconductor layer having an active layer that emits light of a first wavelength that changes depending on driving conditions; and a first reflective layer for the first wavelength; a second reflective layer for a second wavelength disposed on a first surface facing the light emitting surface of the laminated semiconductor layer; a third reflective layer for the first wavelength, disposed on a second surface disposed on the rear side of the optical axis from the first surface; a laser medium disposed between the second reflective layer and the third reflective layer; and a laser medium disposed on the second surface or on the rear side of the optical axis from the second surface.
  • a fourth reflective layer for wavelength comprising a drive unit that controls the drive conditions according to the distance to the target object; The distance measuring device according to (17). (19) The drive unit switches and controls the peak power of the light emission signal emitted from the light source device according to the distance of the target object.
  • the light source device includes: a laminated semiconductor layer having an active layer that emits light of a first wavelength that changes depending on driving conditions; and a first reflective layer for the first wavelength; a second reflective layer for a second wavelength disposed on a first surface facing the light emitting surface of the laminated semiconductor layer; a third reflective layer for the first wavelength, disposed on a second surface disposed on the rear side of the optical axis from the first surface; a laser medium disposed between the second reflective layer and the third reflective layer; and a laser medium disposed on the second surface or on the rear side of the optical axis from the second surface.
  • a fourth reflective layer for wavelength; a first resonator that causes light of the first wavelength to resonate between the first reflective layer and the third reflective layer; a second resonator that resonates light of the second wavelength between the second reflective layer and the fourth reflective layer;
  • the optical axis of the laminated semiconductor layer and the optical axis of the laser medium are arranged on one axis, Distance measurement method.
  • 1 light source device 2 excitation light source, 3 laser medium, 4 saturable absorber, 5 support, 11 first resonator, 12 second resonator, 21 substrate, 22, 24 cladding layer, 23 active layer, 25 contact layer , 51 Mount member, 52 Submount member, 53a, 53b Wiring layer, 54a, 54b Pin, 55a, 55b Wire, 56a, 56b Solder layer, 57, 58 Conductive layer, 59a, 59b Insulating layer, 60 Distance measuring device, 61 Light emitting unit, 62 Drive unit, 63 Power supply circuit, 64 Light emitting side optical system, 65 Light receiving side optical system, 66 Light receiving unit, 67 Signal processing unit, 68 Control unit, 68a Distance measuring unit, 69 Temperature detection unit

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Lasers (AREA)

Abstract

Le problème à résoudre par la présente invention est de permettre un facteur de forme plus faible et une puissance de crête variable. La solution selon l'invention porte sur un dispositif de source de lumière qui comprend : une couche semi-conductrice stratifiée ayant une couche active qui émet une lumière d'une première longueur d'onde, qui est une longueur d'onde qui varie en fonction des conditions d'entraînement, et une première couche réfléchissante pour la première longueur d'onde ; une deuxième couche réfléchissante pour une seconde longueur d'onde disposée sur une première surface faisant face à une surface d'émission de lumière de la couche semi-conductrice stratifiée ; une troisième couche réfléchissante pour la première longueur d'onde disposée sur une seconde surface plus à l'arrière de l'axe optique par rapport à la première surface ; un milieu laser disposé entre la deuxième couche réfléchissante et la troisième couche réfléchissante ; une quatrième couche réfléchissante pour la seconde longueur d'onde disposée sur la seconde surface ou plus à l'arrière de l'axe optique par rapport à la seconde surface ; et un premier résonateur qui fait résonner la lumière de la première longueur d'onde entre la première couche réfléchissante et la troisième couche réfléchissante. L'axe optique de la couche semi-conductrice stratifiée et l'axe optique du milieu laser sont coaxiaux.
PCT/JP2023/029829 2022-08-31 2023-08-18 Dispositif de source de lumière, dispositif de télémétrie et procédé de télémétrie WO2024048325A1 (fr)

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JP2022-138754 2022-08-31

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010085316A (ja) * 2008-10-01 2010-04-15 Topcon Corp レーザ装置および距離測定装置
CN102244356A (zh) * 2011-05-25 2011-11-16 中国工程物理研究院应用电子学研究所 一种双波长快速切换调q激光器
WO2021106757A1 (fr) * 2019-11-28 2021-06-03 ソニー株式会社 Élément laser, procédé de fabrication d'élément laser, dispositif laser et élément d'amplification laser

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010085316A (ja) * 2008-10-01 2010-04-15 Topcon Corp レーザ装置および距離測定装置
CN102244356A (zh) * 2011-05-25 2011-11-16 中国工程物理研究院应用电子学研究所 一种双波长快速切换调q激光器
WO2021106757A1 (fr) * 2019-11-28 2021-06-03 ソニー株式会社 Élément laser, procédé de fabrication d'élément laser, dispositif laser et élément d'amplification laser

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