Light-emitting device

Abstract

Provided is a light-emitting device capable of stably performing desired pulsating light emission.　A light-emitting device according to the present technology comprises: a photonic crystal surface light-emitting element including at least one light-emitting element part having an active layer and a photonic crystal layer; and a mounting substrate on which the photonic crystal surface light-emitting element is mounted. The at least one light-emitting element part includes a first light-emitting element part that is the light-emitting element part provided with a saturable absorption region

Description

Light-emitting device

[0001] The technology according to the present disclosure (hereinafter also referred to as "the technology") relates to a light-emitting device.

[0002] BACKGROUND ART Conventionally, light emitting devices equipped with photonic crystal surface light emitting elements such as photonic crystal surface emitting lasers (PCSELs) and photonic crystal light emitting diodes have been known.

[0003] For example, Non-Patent Document 1 discloses a photonic crystal surface emitting laser in which a saturable absorption region is provided in a light emitting element section including an active layer and a photonic crystal layer.

[0004] Morita, Ryohei, et al. "Photonic-crystal lasers with two-dimensionally arranged gain and loss sections for high-peak-power short-pulse operation." Nature Photonics 15.4 (2021): 311-318.

[0005] However, for example, the photonic crystal surface emitting laser disclosed in Non-Patent Document 1 has room for improvement in terms of stably emitting desired pulsed light.

[0006] Therefore, a main object of the present technology is to provide a light emitting device that can stably emit desired pulsed light.

[0007] The present technology provides a light-emitting device comprising: a photonic crystal surface light-emitting element including at least one light-emitting element portion having an active layer and a photonic crystal layer; and a mounting substrate on which the photonic crystal surface light-emitting element is mounted, wherein the at least one light-emitting element portion includes a first light-emitting element portion that is the light-emitting element portion provided with a saturable absorption region. The light-emitting element portion may be bonded to the mounting substrate via bumps. The mounting substrate may include at least one drive substrate having a driver that drives the photonic crystal surface light-emitting element. The driver may have multiple switching elements. The multiple switching elements may include at least two switching elements connected in parallel to the first light-emitting element portion. The photonic crystal surface light-emitting element may include a substrate on which the light-emitting element portion is provided, and the photonic crystal surface light-emitting element may emit light to the side of the substrate opposite the light-emitting element portion. The first light-emitting element portion may have a non-saturable absorption region that is not the saturable absorption region and is adjacent to the saturable absorption region in-plane. The saturable absorption region and the non-saturable absorption region may be aligned radially of the first light-emitting element portion. The saturable absorption regions and the non-saturable absorption regions may be arranged alternately in the radial direction of the first light-emitting element portion. The non-saturable absorption region may be present in at least a central portion of the first light-emitting element portion in a planar view. The saturable absorption region may be present in at least a peripheral portion of the first light-emitting element portion in a planar view. The mounting substrate may include a first drive substrate having a first driver capable of driving the photonic crystal surface light-emitting element with high power, and a second drive substrate having a second driver capable of driving the photonic crystal surface light-emitting element at high speed. The second drive substrate may be disposed between the first drive substrate and the photonic crystal surface light-emitting element. The first light-emitting element portion may have a first electrode on the mounting substrate side, and the first electrode may be connected to the first driver via a via and a bump penetrating the second drive substrate, and to the second driver via another bump.The photonic crystal surface light emitting device may include a dummy element component disposed spaced apart from the light emitting element component in an in-plane direction, the dummy element component having a second electrode electrically connected to the light emitting element component on the mounting substrate side, the second electrode connected to the first driver via a bonding wire and connected to the second driver via a bump. The at least one light emitting element component may include a second light emitting element component spaced apart from the first light emitting element component in an in-plane direction and not including the saturable absorption region. The mounting substrate may include a first drive substrate including a first driver capable of driving the first light emitting element component with high power, and a second drive substrate including a second driver capable of driving at least the first light emitting element component of the first and second light emitting element components at high speed. The second drive substrate may be disposed between the first drive substrate and the photonic crystal surface light emitting device. The first light emitting element component may have a first electrode on the mounting substrate side, the first electrode connected to the first driver via a via and a bump penetrating the second drive substrate, and connected to the second driver via another bump. The photonic crystal surface light-emitting element may include a dummy element portion disposed apart from the light-emitting element portion in an in-plane direction, the dummy element portion having a second electrode on the mounting substrate side electrically connected to the light-emitting element portion, the second electrode being connected to the first driver via a bonding wire and to the second driver via a bump. The mounting substrate may have at least one driver that drives the first light-emitting element portion, the driver including a first switching element for long-pulse emission and a second switching element for short-pulse emission. The first switching element may perform current modulation operation, and the second switching element may perform Q-switching operation.The first light-emitting element component may have a non-saturable absorption region that is not the saturable absorption region and is adjacent to the saturable absorption region in the plane, the non-saturable absorption region being present in at least a central portion of the first light-emitting element component in a planar view, the saturable absorption region being present in at least a peripheral portion of the first light-emitting element component in a planar view, the first switching element being electrically connected to the central portion, and the second switching element being electrically connected to the peripheral portion. The first light-emitting element component may have an electrode on the mounting substrate side that is electrically connected to the driver, the electrode including a first electrode portion provided on the central portion and connected to the first switching element via a bump, and a second electrode portion provided on the peripheral portion and connected to the second switching element via another bump. The second electrode portion may surround the first electrode portion. The second electrode portion may have multiple portions arranged to surround the first electrode portion. The at least one driver may include a first driver that has the first switching element and is capable of drivability with high power, and a second driver that has the second switching element and is capable of drivability at high speed. A second drive substrate having the second driver may be disposed between a first drive substrate having the first driver and the photonic crystal surface light emitting element. The first light emitting element section may have a first electrode on the mounting substrate side, and the first electrode may be connected to the first driver via a via and a bump penetrating the second drive substrate, and to the second driver via another bump. The photonic crystal surface light emitting element may include a dummy element section disposed spaced apart from the light emitting element section in an in-plane direction, and the dummy element section may have a second electrode on the mounting substrate side electrically connected to the light emitting element section, and the second electrode may be connected to the first driver via a bonding wire, and to the second driver via a bump. The saturable absorption region may be provided in at least the photonic crystal layer and / or the active layer.The first light-emitting element component may have first and second clad layers sandwiching a light-emitting element including the photonic crystal layer and the active layer, and the saturable absorption region may be provided in at least the first clad layer and / or the second clad layer. The first light-emitting element component may have a reflector on the mounting substrate side of the light-emitting element including the photonic crystal layer and the active layer, and the saturable absorption region may be provided in at least the reflector.

[0008] 17 is a cross-sectional view of a light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 18 is a plan view of a photonic crystal surface light-emitting element of a light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 19 is a diagram for explaining a problem of the conventional technology. FIG. 20 is a diagram for explaining control of a repetition frequency by a laser driver. FIG. 21 is a flowchart for explaining an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 22 is a cross-sectional view of each process of an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 23 is a cross-sectional view of each process of an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 24 is a cross-sectional view of each process of an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 25 is a cross-sectional view of each process of an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 26 is a cross-sectional view of each process of an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 27 is a cross-sectional view of each process of an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 28 is a cross-sectional view of each process of an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 29 is a cross-sectional view of each process of an example of a manufacturing method of the light-emitting device of FIG. 1. FIG. 21 is a partial cross-sectional view of a light-emitting device according to Example 3 of an embodiment of the present technology. FIG. 22 is a schematic plan view of a light-emitting device according to Example 3 of an embodiment of the present technology. FIG. 23 is a diagram for explaining a function of the light-emitting device of FIG. 20. FIG. 24 is a partial cross-sectional view of a light-emitting device according to Example 4 of an embodiment of the present technology. FIG. 25 is a plan view of a photonic crystal surface light-emitting element of a light-emitting device according to Example 4 of an embodiment of the present technology. FIG. 26 is a schematic plan view of a light-emitting device according to Example 4 of an embodiment of the present technology. FIG. 27 is a diagram showing Configuration Example 1 of an anode electrode of the light-emitting device of FIG. 23. FIG. 28 is a diagram showing Configuration Example 2 of an anode electrode of the light-emitting device of FIG. 23. FIG. 29 is a partial cross-sectional view of a light-emitting device according to Example 5 of an embodiment of the present technology. FIG. 29 is a schematic plan view of a light-emitting device according to Example 5 of an embodiment of the present technology. FIG. 29 is a cross-sectional view of a light-emitting device according to Example 6 of an embodiment of the present technology. FIG. 29 is a cross-sectional view of a light-emitting device according to Example 7 of an embodiment of the present technology. FIG. 29 is a plan view of a photonic crystal surface light-emitting element of a light-emitting device according to Example 7 of an embodiment of the present technology. FIG. 29 is a cross-sectional view of a light-emitting device according to Example 8 of an embodiment of the present technology.Fig. 10 is a cross-sectional view of a light emitting and receiving device according to Example 9 of an embodiment of the present technology. Fig. 11 is a diagram showing an example of application of the light emitting device of Fig. 1 to a distance measurement device. Fig. 12 is a block diagram showing an example of a schematic configuration of a vehicle control system. Fig. 13 is an explanatory diagram showing an example of an installation position of a distance measurement device.

[0009] Preferred embodiments of the present technology will be described in detail below with reference to the accompanying drawings. Note that in this specification and the drawings, components having substantially the same functional configurations will be denoted by the same reference numerals, and redundant description will be omitted. The embodiments described below illustrate typical embodiments of the present technology, and are not intended to narrow the scope of the present technology. Even when it is described in this specification that a light-emitting device according to the present technology achieves multiple effects, it is sufficient that the light-emitting device according to the present technology achieves at least one effect. The effects described in this specification are merely examples and are not limiting, and other effects may also be achieved.

[0010] The description will be made in the following order: 0. Introduction 1. Light-emitting device according to Example 1 of one embodiment of the present technology 2. Light-emitting device according to Example 2 of one embodiment of the present technology 3. Light-emitting device according to Example 3 of one embodiment of the present technology 4. Light-emitting device according to Example 4 of one embodiment of the present technology 5. Light-emitting device according to Example 5 of one embodiment of the present technology 6. Light-emitting device according to Example 6 of one embodiment of the present technology 7. Light-emitting device according to Example 7 of one embodiment of the present technology 8. Light-emitting device according to Example 8 of one embodiment of the present technology 9. Light-emitting and receiving device according to Example 9 of one embodiment of the present technology 10. Modified examples of the present technology 11. Application example to electronic device 12. Example in which the light-emitting device is applied to a distance measurement device 13. Example in which the distance measurement device is mounted on a moving body

[0011] <0. Introduction> In the application of semiconductor lasers to Direct ToF (dToF) systems, the power, pulse width, and repetition frequency on the Tx side (transmitting side) and the bin width on the Rx side (receiving side) are adjusted for each application, such as long-distance ranging or short-distance ranging. For example, the ranging range can be confirmed by measuring at different repetition frequencies. For long-distance ranging, the Tx side pulse width, pulse energy, and Rx side bin width are set to be large. For short-distance high-precision ranging, the Tx side pulse width, pulse energy, and Rx side bin width are set to be small. In this way, it is necessary to adjust the parameters of the emitted pulse (e.g., repetition frequency, pulse width, pulse energy, bin width, etc.) to emit the desired pulse light according to the ranging range and the required ranging accuracy.

[0012] For example, in the case of conventional Q-switched semiconductor lasers (e.g., JP 2017-123429 A), the repetition frequency is determined by the intensity of the excitation current, the junction temperature, and the amount of saturable absorber, which means that the repetition frequency cannot be adjusted significantly for each application. Furthermore, the pulse width can only be adjusted by about ±5 ps with the excitation current intensity, which means that the pulse width cannot be adjusted significantly (e.g., 100 ps or more) for each application. In other words, conventional Q-switched semiconductor lasers have room for improvement in terms of achieving desired pulse emission (transmission of an emission pulse with desired parameters).

[0013] Furthermore, Q-switching operation has the problem of large jitter (fluctuations in the repetition frequency period) because fluctuations in the excitation current and junction temperature cause deviations in the timing of pulse oscillation (see Figure 3). In other words, conventional Q-switched semiconductor lasers have room for improvement in terms of stably emitting pulses.

[0014] The above-mentioned problems also exist in conventional PCSELs (e.g., Non-Patent Document 1) that have a saturable absorption region provided in the resonator. In other words, conventional PCSELs have room for improvement in terms of stably emitting desired pulsed light.

[0015] Therefore, after extensive research, the inventors have succeeded in stably emitting the desired pulsed light by mounting a photonic crystal surface light-emitting device provided with a saturable absorption region on a mounting substrate, which is a novel finding of the inventors.

[0016] The inventors then developed a light emitting device according to the present technology as a light emitting device that embodies this new finding.

[0017] In particular, in the case of a PCSEL (photonic crystal surface-emitting laser), which has a large light-emitting area and a large threshold current (up to 500 mA), it is required to adjust the excitation current more accurately and quickly than a general VCSEL (current threshold up to 10 mA).The light-emitting device according to the present technology can meet such requirements because the photonic crystal surface-emitting element is mounted on a mounting substrate.

[0018] Hereinafter, a light emitting device according to an embodiment of the present technology will be described in detail using several examples as examples. In the following, in cross-sectional views such as FIG. 1 , the upper side will be referred to as "up" and the lower side will be referred to as "down" as appropriate.

[0019] 1. Light-emitting device according to Example 1 of an embodiment of the present technology> Fig. 1 is a cross-sectional view of a light-emitting device 1 according to Example 1 of an embodiment of the present technology. Fig. 2 is a plan view (view from the mounting substrate 20 side) of a photonic crystal surface light-emitting element 10 of the light-emitting device 1.

[0020] <Configuration of Light-Emitting Device> As shown in Figures 1 and 2 as an example, a light-emitting device 1 according to Example 1 of an embodiment of the present technology includes a photonic crystal surface light-emitting element 10 including at least one (e.g., one) light-emitting element section LE having an active layer 104 and a photonic crystal layer 106, and a mounting substrate 20 on which the photonic crystal surface light-emitting element 10 is mounted.

[0021] An example of the photonic crystal surface light emitting element 10 is a photonic crystal-surface emitting laser (PCSEL). An example of the photonic crystal surface light emitting element 10 is a rear surface emitting photonic crystal surface emitting laser. An example of the oscillation wavelength λ of the photonic crystal surface light emitting element 10 is in the NIR (Near Infrared Ray) band, for example, 940 nm.

[0022] The photonic crystal surface light emitting element 10 includes a substrate 101. A light emitting element section LE is provided on the substrate 101. The photonic crystal surface light emitting element 10 emits light to the side (upper side) opposite to the light emitting element section LE side of the substrate 101. In other words, the surface of the substrate 101 opposite to the light emitting element section LE side is the emission surface. An AR film 114 (anti-reflection film) is provided on the emission surface. Note that the AR film 114 is not essential.

[0023] As an example, photonic crystal surface light emitting device 10 is flip-chip mounted (junction-down mounted) on mounting substrate 20. That is, in photonic crystal surface light emitting device 10, light emitting element section LE is bonded to mounting substrate 20 via bumps. In this way, photonic crystal surface light emitting device 10 is electrically and mechanically connected to mounting substrate 20.

[0024] The mounting substrate 20 is, for example, a substrate (drive substrate) having a laser driver (laser drive circuit) or a wiring substrate electrically connected to the laser driver. Here, the mounting substrate 20 is a drive substrate. The laser driver of the mounting substrate 20 has, for example, an nMOS (n-type Metal-Oxide-Semiconductor Field-effect Transistor) as a switching element. In particular, by using an nMOS as the switching element, the switching element can be made smaller, leading to a smaller laser driver and improved design freedom. Note that the laser driver may have a pMOS (p-type Metal-Oxide-Semiconductor Field-effect Transistor) instead of an nMOS.

[0025] As an example, the photonic crystal surface light emitting device 10 includes a dummy element portion DE arranged alongside the light emitting element portion LE in the in-plane direction on the substrate 101. The dummy element portion DE is also called a "non-light emitting element portion."

[0026] The light-emitting element unit LE has an anode electrode 111 as a first electrode on the mounting substrate 20 side. The dummy element unit DE has a part of a cathode wiring 113 as a second electrode electrically connected to the light-emitting element unit LE on the mounting substrate 20 side.

[0027] In the light-emitting element section LE, as an example, the active layer 104 and the photonic crystal layer 106 are stacked on top of each other (for example, arranged close to each other in the stacking direction). The light-emitting section is configured to include the active layer 104 and the photonic crystal layer 106. Here, the active layer 104 is arranged on the substrate 101 side (lower side, for example, n-side) of the photonic crystal layer 106, but the active layer 104 may also be arranged on the opposite side of the photonic crystal layer 106 from the substrate 101 side (upper side, for example, p-side). Note that when the active layer 104 is arranged on the n-side of the photonic crystal layer 106, the electrical characteristics are improved compared to when it is arranged on the p-side.

[0028] The light-emitting element section LE has first and second cladding layers 103 and 107 that sandwich a light-emitting section including an active layer 104 and a photonic crystal layer 106. The first cladding layer 103 is disposed on the substrate 101 side (upper side) of the light-emitting section, and the second cladding layer 107 is disposed on the opposite side of the light-emitting section from the substrate 101 side (lower side).

[0029] In the light emitting element section LE, a resonator is configured, for example, including an active layer 104, a photonic crystal layer 106, and first and second clad layers 103 and 107.

[0030] The light-emitting element section LE further has a first contact layer 102 arranged on the substrate 101 side (upper side) of the resonator, a reflector 108 arranged on the opposite side (lower side) of the resonator from the substrate 101 side, and a second contact layer 109 arranged on the opposite side (lower side) of the reflector 108 from the resonator side.

[0031] That is, in the light emitting element section LE, a first contact layer 102, a first cladding layer 103, an active layer 104, a photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108 and a second contact layer 109 are arranged in this order on a substrate 101.

[0032] The light-emitting element section LE has a light-emitting mesa LM including at least a part (for example, the entirety) of the resonator. Here, the light-emitting mesa LM is provided to protrude from the first contact layer 102, and is configured to include a first cladding layer 103, an active layer 104, a photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108, and a second contact layer 109. Here, the light-emitting mesa LM is cylindrical, but it may also be in the shape of a truncated cone, an elliptical cylinder, an elliptical truncated cone, a polygonal pillar, a polygonal truncated pyramid, or the like.

[0033] The dummy element portion DE is configured in a similar manner to the light-emitting element portion LE and includes a dummy mesa DM. The dummy mesa DM is also called a "non-light-emitting mesa" or "pedestal portion." Here, the dummy mesa DM protrudes from the first contact layer 102 and includes a first cladding layer 103, an active layer 104, a base material 106BM of the photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108, and a second contact layer 109.

[0034] The light emitting mesa LM and the dummy mesa DM are covered with an insulating film 110. For example, the insulating film 110 does not cover the center of the top of the light emitting mesa LM (specifically, the second contact layer 109), and an anode electrode 111 (p-side electrode) is provided on this center. For example, the insulating film 110 does not cover a portion of the first contact layer 102 between the light emitting element portion LE and the dummy element portion DE, and a cathode electrode 112 (n-side intermediate electrode) is provided on this portion. A cathode wiring 113 for cathode pull-up is provided along the dummy mesa DM covered with the insulating film 110. One end of the cathode wiring 113 contacts the cathode electrode 112, an intermediate portion is provided on the side surface of the dummy mesa DM via the insulating film 110, and a second electrode, which is the portion on the other end, is provided on the top of the dummy mesa DM (specifically, the second contact layer 109) via the insulating film 110.

[0035] That is, photonic crystal surface light emitting device 10 has an intra-cavity structure in which anode electrode 111 , cathode electrode 112 and cathode wiring 113 are provided on the same surface (upper surface) of substrate 101 .

[0036] At least one light-emitting element element LE includes a first light-emitting element element that is a light-emitting element element provided with a saturable absorber region (SAR). Hereinafter, the first light-emitting element element is also referred to as the "first light-emitting element element LE." Hereinafter, there are multiple (e.g., two) saturable absorber regions SAR (e.g., first and second saturable absorber regions SAR1 and SAR2, see the light-shaded areas in FIG. 1 and FIG. 2).

[0037] (Substrate) The substrate 101 is, for example, a semiconductor substrate containing impurities, a semi-insulating substrate (e.g., a semiconductor substrate containing no impurities), or the like. Here, the substrate 101 is made of GaAs. In order to reduce light absorption, the substrate 101 is preferably made of, for example, lightly doped GaAs (n-GaAs or p-GaAs), SI (Semi-Insulating)-GaAs, or the like. Furthermore, the substrate 101 is preferably transparent to the emission wavelength of the active layer 104.

[0038] (AR Film) The AR film 114 has, for example, a laminated structure in which a plurality of dielectric films (for example, SiO2 film, SiN film, SiON film, etc.) are laminated.

[0039] (First Contact Layer) The first contact layer 102 is, for example, an Al layer of a first conductivity type (for example, n-type). x0 Ga 1-x0 The first contact layer 102 is made of, for example, n-GaAs (0≦x0<1). The first contact layer 102 contains an n-type impurity such as silicon (Si). The first contact layer 102 not only makes an ohmic contact between the first cladding layer 103 and the cathode electrode 112, but also functions as a current diffusion layer that allows current to reach the center of the light emitting element portion LE.

[0040] (First Cladding Layer) The first cladding layer 103 is, for example, an Al layer of a first conductivity type (for example, n-type). x1 Ga 1-x1The first cladding layer 103 is made of As (0≦x1<1). The cladding layer is also called a “spacer layer.” The first cladding layer 103 contains an n-type impurity such as silicon (Si).

[0041] (Active Layer) The active layer 104 has, for example, a quantum well structure including a barrier layer and a well layer made of a GaAs-based compound semiconductor. x2 Ga 1-x2 A well layer made of As (0<x2<1) and undoped In x3 Ga 1-x3 The active layer 104 has a multiple quantum well structure (MQW structure) in which barrier layers made of As (0<x3<1) are alternately stacked. Instead of the multiple quantum well structure, the active layer 104 may have a single quantum well structure (QW structure), a quantum dot structure, a quantum wire structure, or the like. The emission wavelength of the active layer 104 is, for example, 935 nm. The active layer is also called an "emitting layer."

[0042] (Photonic Crystal Layer) The photonic crystal layer 106 provides a photonic crystal resonance and diffraction effect to the light emitted from the active layer 104 adjacent in the stacking direction.

[0043] The photonic crystal layer 106 includes, for example, a base portion 106b that is a part of a plate-shaped base material 106BM (see FIG. 6 ), and a modified refractive index periodic structure 106a that is arranged on the base portion 106b. In the modified refractive index periodic structure 106a, modified refractive index areas (e.g., holes (air or vacuum)) are arranged periodically (e.g., in a two-dimensional lattice pattern) along the in-plane direction of the base portion 106b. The modified refractive index periodic structure 106a generates a periodic refractive index distribution in the photonic crystal layer 106. In the photonic crystal layer 106, the period (e.g., lattice spacing, lattice constant, hole spacing) of the modified refractive index areas is, for example, the same as or close to the emission wavelength of the active layer 104. The material of the base material 106BM is, for example, Al. x5 Ga 1-x5 The modified refractive index periodic structure 106 a is preferably, but not limited to, GaAs (0≦x5<1), for example. Here, the modified refractive index periodic structure 106 a is provided at a position corresponding to the central part in the plane of the active layer 104, but may be provided at a position corresponding to the entire area in the plane of the active layer 104.

[0044] Due to the presence of the periodic refractive index distribution described above, light of a specific wavelength (e.g., oscillation wavelength λ) forms a two-dimensional standing wave state in a specific direction within the photonic crystal plane within the photonic crystal layer 106. In the photonic crystal layer 106, diffraction occurs not only in directions parallel to the photonic crystal plane but also in directions perpendicular thereto, allowing a beam with a narrow exit angle to be emitted in a direction intersecting the in-plane direction (e.g., perpendicular to the plane), thereby providing a surface emission output.

[0045] The photonic crystal layer 106 can control the intensity and emission direction of the beam by adjusting the positions and areas of the holes (air holes) and the modulation amounts thereof.

[0046] (Second Cladding Layer) The second cladding layer 107 is, for example, an AlN layer of a second conductivity type (for example, p-type). x6 Ga 1-x6 The second cladding layer 107 is made of As (0≦x6<1). The cladding layer is also called a “spacer layer.” The second cladding layer 107 contains a p-type impurity such as carbon (C).

[0047] (Reflector) Reflector 108 is provided to reflect light emitted from the light emitting section including active layer 104 and photonic crystal layer 106 to the opposite side (lower side) from substrate 101 toward substrate 101 (upper side) and use it as emitted light (to improve light utilization efficiency). In this way, reflector 108 is provided to improve efficiency and is not essential.

[0048] The reflecting mirror 108 is, for example, a semiconductor multilayer reflecting mirror. A multilayer reflecting mirror is also called a distributed Bragg reflector. More specifically, the reflecting mirror 108 is, for example, a second conductivity type (for example, p-type) semiconductor multilayer reflecting mirror, and has a structure in which a plurality of types (for example, two types) of semiconductor layers having different refractive indices are alternately stacked with an optical thickness of ¼ wavelength of the emission wavelength. Each refractive index layer of the reflecting mirror 108 is made of an AlGaAs-based compound semiconductor of the second conductivity type (for example, p-type). Specifically, the reflecting mirror 108 has a low refractive index layer made of, for example, p-Al x7 Ga 1-x7 As (0<x7<1), and the high refractive index layer is, for example, p-Alx8 Ga 1-X8 As (0≦x8<x7).

[0049] (Second Contact Layer) The second contact layer 109 is, for example, an Al layer of a second conductivity type (for example, p-type). x9 Ga 1-x9 The second contact layer 109 is made of As (0≦x9<1), for example, p-GaAs. The second contact layer 109 contains a p-type impurity such as carbon (C). The second contact layer 109 is a layer for making ohmic contact between the reflecting mirror 108 and the anode electrode 111.

[0050] (Insulating Film) The insulating film 110 is made of a dielectric material such as SiN, SiO2, SiON, etc. In particular, when the insulating film 110 is made of SiN, it contributes to suppressing the penetration of moisture from the outside.

[0051] (Anode Electrode) The anode electrode 111 serving as the first electrode (p-side electrode) is, for example, configured to include a non-alloy metal film. Specifically, the anode electrode 111 has a laminated structure in which, for example, a Ti layer and an Au layer are laminated in this order from the second contact layer 109 side. Note that the anode electrode 111 may further have a Pt layer laminated on the Au layer to improve solderability. The anode electrode 111 is electrically connected to the anode terminal 22a of the mounting substrate 20 via a first bump B1.

[0052] The cathode electrode 112 serving as an n-side intermediate electrode is, for example, made of an alloy. Specifically, the cathode electrode 112 has a layered structure in which, for example, an AuGe layer, a Ni layer, and an Au layer are layered in this order from the first contact layer 102 side.

[0053] (Cathode Wiring) The cathode wiring 113, which is a part of the second electrode (n-side electrode), is made of, for example, Au plating, Ag plating, Al plating, etc. The thickness of the cathode wiring 113 is preferably a thickness that can sufficiently suppress voltage drop. The second electrode of the cathode wiring 113 is electrically connected to the cathode terminal 22b of the mounting substrate 20 via a second bump B2.

[0054] (Bumps) Each of the first and second bumps B1 and B2 is a conductive bump having electrical conductivity, and is made of a metal such as Ag, Au, Cu, or Ni, or a Pb-free solder such as AgSn, AuSn, CuSn, NiSn, or CuNiSn.

[0055] (Mounting Substrate) The mounting substrate 20 (e.g., a laser driver) includes, as an example, a semiconductor substrate 21 (e.g., a p-type semiconductor substrate), a plurality of (e.g., two) nMOSs provided on the semiconductor substrate 21, which are connected in parallel to the first light-emitting element unit LE and can be driven in parallel, a gate voltage control unit, and a current source. The sources of the plurality of (e.g., two) nMOSs are connected to the anode terminal 22a of the mounting substrate 20, and their drains are connected to the current source. A gate voltage (pulse voltage) is synchronously applied to each gate from the gate voltage control unit. The gate voltage control unit controls the parameters of the gate voltage (e.g., pulse width and repetition frequency) to control the parameters of the current pulse (e.g., pulse width and repetition frequency). The current source may be a constant current source or a variable current source; however, a variable current source is preferable because the current value is variable and the intensity (pulse amplitude) of the current pulse can be adjusted. Examples of the semiconductor substrate 21 include a Si substrate, a Ge substrate, an SOI substrate, and a GOI substrate. Note that MOS is an abbreviation for MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0056] On the mounting substrate 20, multiple (e.g., two) nMOSs synchronously generate current pulses as drive pulses for emitting / extinguishing light in the first light-emitting element unit LE, and can be applied simultaneously to the light-emitting element unit LE (first light-emitting element unit LE).

[0057] (Regarding Repetition Frequency Control by Laser Driver) FIG. 4 is a diagram for explaining repetition frequency control by a laser driver.

[0058] As shown in Figure 4A, when the pulse width of the excitation current (current pulse) is longer than the pulse period (≦1 ns) determined by the intensity (pulse amplitude) of the excitation current, the junction temperature (temperature of the active layer), and the amount of saturable absorber (condition 1), the repetition frequency becomes a fixed value.

[0059] On the other hand, as shown in Figure 4B, when the pulse width of the excitation current (current pulse) is shorter than the pulse period (≦1 ns) determined by the intensity (pulse amplitude) of the excitation current, the junction temperature, and the amount of saturable absorber (condition 2), the repetition frequency can be controlled. In this case, the repetition frequency of the optical pulse and the repetition frequency of the current pulse are the same.

[0060] Furthermore, when a rapid rise in the current pulse can be achieved as shown in Figure 4C (condition 3), for example, by driving multiple switching elements in parallel (synchronous driving), the more rapid the rise in the current pulse, the more jitter can be suppressed. Note that the threshold current Ith of a VCSEL is on the order of 10 mA or less, and the threshold current Ith of a PCSEL is on the order of 500 mA or less. As described above, the light-emitting device 1 can drive multiple MOSs in parallel, and therefore satisfies condition 3.

[0061] A saturable absorber (SA) is a material that acts as an absorber for low-intensity incident light and acts as a transparent material for high-intensity incident light, saturating its absorbing ability. Therefore, a saturable absorber can shorten the pulse length of incident light. By appropriately adjusting the power at which the saturable absorber saturates and the carrier lifetime (a coefficient related to the time required for saturation), it is possible to generate pulsed light called a Q-switched pulse with a pulse width of 30 ps to 100 ps. For a given saturable absorber, the pulse width and repetition period of the Q-switched pulse can be adjusted by changing the drive pulse (current pulse). The pulse width of the Q-switched pulse is generally in the range of 30 ps to 100 ps, ​​and the repetition period is generally in the range of 500 ps to 2 ns (repetition frequency: 0.5 GHz to 2 GHz).

[0062] (Saturable Absorption Region and Non-Saturable Absorption Region) As an example, the first and second saturable absorption regions SAR1 and SAR2 have first and second saturable absorption regions SAR1 and SAR2 aligned in the radial direction of the light emitting mesa LM. The first and second saturable absorption regions SAR1 and SAR2 are both circumferentially shaped (e.g., annularly shaped) in a plan view and aligned in the radial direction (e.g., concentrically) of the light emitting mesa LM. Here, the second region SAR2 is located radially outward of the first region SAR1 and surrounds the first region SAR1. Each saturable absorption region SAR is an ion-implanted region into which ions are implanted.

[0063] As an example, the saturable absorption regions SAR and the non-saturable absorption regions NSAR are arranged in the radial direction of the light-emitting element portion LE. More specifically, the saturable absorption regions SAR and the non-saturable absorption regions NSAR are arranged alternately in the radial direction of the light-emitting element portion LE.

[0064] More specifically, the first light-emitting element component LE1, for example, has, in addition to the saturable absorption region SAR, a non-saturable absorption region NSAR (Non-Saturable Absorption Region) that is not a saturable absorption region and is adjacent to the saturable absorption region SAR in the plane. Here, there are a plurality of (e.g., two) non-saturable absorption regions NSAR (e.g., first and second non-saturable absorption regions NSAR1, NSAR2). The first non-saturable absorption region NSAR1 is located on the inner diameter side of the first saturable absorption region SAR1. The second non-saturable absorption region NSAR2 is located between the first and second saturable absorption regions SAR1, SAR2. The first non-saturable absorption region NSAR1 is, for example, a circular region in a plan view, and the second non-saturable absorption region NSAR2 is, for example, a circular region in a plan view. Each non-saturable absorption region NSAR is a non-ion-implanted region, which is a region into which ions are not implanted.

[0065] For example, the first non-saturable absorption region NSAR1 is disposed in the center of the light-emitting element unit LE, where the current density is highest when driven, in a plan view. This allows high-power, long-pulse light to be output from the first non-saturable absorption region NSAR1. This high-power, long-pulse light is suitable, for example, as laser light for long-distance ranging.

[0066] For example, the first saturable absorption region SAR1 is disposed in a position adjacent to the outer peripheral edge of the first non-saturable absorption region NSAR1 in the peripheral portion of the light-emitting element portion LE, where the current density becomes relatively high during operation, in a plan view. This enables medium-power, short-pulse light to be output from the first saturable absorption region SAR1. This medium-power, short-pulse light is suitable, for example, as laser light for medium-distance, high-precision distance measurement.

[0067] For example, the second non-saturable absorption region NSAR2 is disposed in a position adjacent to the outer peripheral edge of the first saturable absorption region SAR1 in the peripheral portion of the light-emitting element component LE where the current density is relatively low during operation in a plan view. This enables medium-power, long-pulse light to be output from the second non-saturable absorption region NSAR2. This medium-power, long-pulse light is suitable as laser light for, for example, medium-distance distance measurement.

[0068] For example, the second saturable absorption region SAR2 is disposed in a position adjacent to the outer peripheral edge of the second non-saturable absorption region NSAR2 in the peripheral portion of the light-emitting element component LE where the current density is lowest during operation in a plan view. This enables low-power short-pulse light to be output from the second saturable absorption region SAR2. This low-power short-pulse light is suitable as laser light for, for example, short-distance high-precision distance measurement.

[0069] First saturable absorption region SAR1 is provided across active layer 104, photonic crystal layer 106, second cladding layer 107, reflecting mirror 108, and second contact layer 109, for example.

[0070] <Operation of Light-Emitting Device> The operation of the light-emitting device 1 will be described below. In the light-emitting device 1, a current pulse is generated in each nMOS of the mounting substrate 20, with parameters set to satisfy Condition 2 above. When a gate voltage (pulse voltage) is synchronously applied to each nMOS, a current pulse is synchronously generated in each nMOS due to current from the anode side of the current source, and a current pulse with a sharp rise is applied to the light-emitting element unit LE. The current applied to the light-emitting element unit LE is injected into the active layer 104 via the anode electrode 111, the second contact layer 109, the reflecting mirror 108, the second cladding layer 107, and the photonic crystal layer 106, in this order. At this time, the active layer 104 emits light, and the light forms a standing wave in the in-plane direction within the photonic crystal layer 106. When the resonance condition is satisfied, light is emitted from the photonic crystal layer 106 toward the substrate 101 and the side opposite the substrate 101. The light emitted toward the substrate 101 is directly emitted as laser light from the back surface of the substrate 101. The light emitted toward the side opposite to the substrate 101 side is reflected by the reflecting mirror 108 toward the substrate 101 side and is emitted as laser light from the back surface of the substrate 101. At this time, the laser light generated by laser oscillation in each saturable absorption region SAR becomes short-pulse light (pulse width on the order of about 10 ps), and the laser light generated by laser oscillation in each non-saturable absorption region NSAR becomes long-pulse light (pulse width on the order of about 100 ps). In other words, laser light that is a mixture of short-pulse light and long-pulse light is emitted from the photonic crystal surface light-emitting element 10. Furthermore, the pulse width and repetition frequency of the current pulse can be adjusted by controlling the gate voltage with the gate voltage control unit, and the pulse amplitude of the current pulse can be adjusted by controlling the current value with the current source (in the case of a variable current source). The current that has passed through the active layer 104 flows through the first cladding layer 103 , the first contact layer 102 , the cathode electrode 112 and the cathode wiring 113 in this order, and is then output to the cathode side of the current source of the mounting substrate 20 .

[0071] <<Method of Manufacturing Light-Emitting Device>> A method of manufacturing the light-emitting device 1 will be described below with reference to the flowchart in Fig. 5 and the like. The overall flow is as follows: first, a semiconductor manufacturing method using semiconductor manufacturing equipment is used to simultaneously produce multiple photonic crystal surface light-emitting elements 10 on a single wafer (hereinafter referred to as "substrate 101" for convenience), which is the base material of the substrate 101. Next, the multiple, integrated photonic crystal surface light-emitting elements 10 are separated from each other by dicing (e.g., stealth dicing) to obtain chip-shaped photonic crystal surface light-emitting elements 10. Finally, the photonic crystal surface light-emitting elements 10 are flip-chip mounted on a mounting substrate 20.

[0072] In the first step S1, a stack is formed (see FIG. 6). Specifically, a stack is formed by stacking a first contact layer 102, a first cladding layer 103, an active layer 104, and a base material 106BM of the photonic crystal layer 106 in this order on a substrate 101 (e.g., an n-GaAs substrate, an SI-GaAs substrate, etc.) using an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition). Methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn) and arsine (AsH) gas are used as compound semiconductor raw materials. Disilane (SiH) is used as a donor impurity raw material, and carbon tetrabromide (CBr) is used as an acceptor impurity raw material.

[0073] In the next step S2, the photonic crystal layer 106 is formed (see FIG. 7 ). Specifically, a resist pattern for forming the modified refractive index periodic structure 106a of the photonic crystal layer 106 is formed on the stack (on the base material 106BM of the photonic crystal layer 106) by photolithography, and the base material 106BM is etched to a predetermined depth using the resist pattern as a mask, thereby forming the modified refractive index periodic structure 106a on the base portion 106b. At this time, it is preferable to use RIE (Reactive Ion Etching) using, for example, a Cl-based gas. The resist pattern is then removed.

[0074] In the next step S3, second cladding layer 107, reflecting mirror 108, and second contact layer 109 are laminated (see FIG. 8). Specifically, second cladding layer 107, reflecting mirror 108, and second contact layer 109 are laminated in this order by another epitaxial growth on the laminate (see FIG. 7) on which photonic crystal layer 106 has been formed.

[0075] In the next step S4, the light emitting mesa LM and the dummy mesa DM are formed (see FIG. 9). Specifically, a resist pattern for forming the light emitting mesa LM and the dummy mesa DM is formed on the stacked body (see FIG. 8) by photolithography, and the stacked body is etched by dry etching or wet etching using the resist pattern as a mask. The etching depth here is set to, for example, until the first contact layer 102 is exposed. Thereafter, the resist pattern is removed.

[0076] In the next step S5, the saturable absorption region SAR is formed (see FIG. 10 ). Specifically, a resist pattern is formed on the light emitting mesa LM (specifically, on the second contact layer 109) of the stack (see FIG. 9 ) in which the light emitting mesa LM and the dummy mesa DM are formed, covering the region other than the region where the first and second saturable absorption regions SAR1 and SAR2 will be formed. Ion implantation is performed using the resist pattern as a mask. The depth of the ion implantation at this time is set to, for example, reach the top surface of the first cladding layer 103. As a result, the first and second saturable absorption regions SAR1 and SAR2 are formed in the light emitting mesa LM.

[0077] In the next step S6, the anode electrode 111 and the cathode electrode 112 are formed (see FIG. 11 ). Specifically, the anode electrode 111 is formed on the center of the top of the light-emitting mesa LM (more specifically, the second contact layer 109) by, for example, a lift-off method. The cathode electrode 112 is formed on the region of the first contact layer 102 between the region where the light-emitting mesa LM protrudes and the region where the dummy mesa DM protrudes by, for example, a lift-off method. The electrode materials for the anode electrode 111 and the cathode electrode 112 are formed by, for example, evaporation, sputtering, or the like.

[0078] In the next step S7, an insulating film 110 is formed (see FIG. 12). Specifically, first, the insulating film 110 is formed over the entire surface of the stack (see FIG. 11) on which the anode electrode 111 and the cathode electrode 112 are formed, for example, by CVD (Chemical Vapor Deposition), sputtering, evaporation, or the like. Next, the insulating film 110 covering the anode electrode 111 and the cathode electrode 112 is removed by photolithography and etching to expose the anode electrode 111 and the cathode electrode 112.

[0079] Alternatively, instead of steps S6 and S7, an insulating film 110 may be formed before the anode electrode 111 and the cathode electrode 112 are formed on the laminate, and contact holes for forming the anode electrode 111 and the cathode electrode 112 may be formed in the insulating film 110, and electrodes corresponding to each contact hole may be formed by, for example, lift-off.

[0080] In the next step S8, the cathode wiring 113 is formed (see FIG. 13 ). Specifically, the cathode wiring 113 is formed by, for example, plating so that one end contacts the cathode electrode 112, the other end covers the top of the dummy mesa DM via the insulating film 110, and the middle part covers the side of the dummy mesa DM via the insulating film 110. Note that, prior to plating, it is preferable to form a seed layer in the area to be plated.

[0081] In the final step S9, an AR film 114 (anti-reflection film) is formed (see FIG. 14 ). Specifically, first, the back surface of the substrate 101 is ground using, for example, a grinder or a CMP (Chemical Mechanical Polisher) device to thin it. Next, the AR film 114 is formed on the back surface of the thinned substrate 101 by, for example, sputtering or vapor deposition. Thereafter, the substrate 101 is diced to obtain a plurality of chip-shaped photonic crystal surface light-emitting devices 10. Note that, before dicing, it is preferable to remove the portion of the insulating film 110 to be diced.

[0082] In the final step S10, flip-chip mounting is performed (see FIGS. 15 and 16). Specifically, first, a first bump B1 is attached to the anode terminal 22a of the mounting substrate 20, and a second bump B2 is attached to the cathode terminal 22b (see FIG. 15). Next, the photonic crystal surface light emitting device 10 and the mounting substrate 20 are aligned so that the anode electrode 111 faces the first bump B1 and the cathode wiring 113 faces the second bump B2 (see FIG. 15). Next, the photonic crystal surface light emitting device 10 and the mounting substrate 20 are thermocompression bonded (bonded by applying pressure while heating) via the first and second bumps B1 and B2. As a result, the photonic crystal surface light emitting device 10 and the mounting substrate 20 are electrically and mechanically connected via the first and second bumps B1 and B2 (see FIG. 16).

[0083] In step S10, each bump is attached to the mounting substrate 20 side, but each bump may be attached to the photonic crystal surface light-emitting element 10 side, or bumps (of the same material or different materials) may be attached to both the mounting substrate 20 side and the photonic crystal surface light-emitting element 10 side.

[0084] <Effects of Light-Emitting Device> Effects of the light-emitting device 1 according to Example 1 of an embodiment of the present technology will be described below.

[0085] The light-emitting device 1 comprises a photonic crystal surface light-emitting element 10 including at least one light-emitting element portion LE having an active layer 104 and a photonic crystal layer 106, and a mounting substrate 20 on which the photonic crystal surface light-emitting element 10 is mounted, and at least one light-emitting element portion LE includes a first light-emitting element portion LE which is a light-emitting element portion LE provided with a saturable absorption region SAR.

[0086] In the light emitting device 1, a photonic crystal surface light emitting element 10 including a first light emitting element section LE provided with a saturable absorption region SAR is mounted on a mounting substrate 20, so that desired pulsed light emission is possible and high-speed current adjustment is possible, thereby suppressing jitter.

[0087] As a result, the light emitting device 1 can provide a light emitting device that can stably emit desired pulsed light.

[0088] Furthermore, the light emitting device 1 has a mounting substrate 20 having multiple (e.g., two) nMOSs. In this case, each nMOS can be driven in parallel (synchronously) to generate a current pulse with a sharp rise, thereby further suppressing jitter. This leads to further stabilization of pulsed light emission.

[0089] Furthermore, since the mounting substrate 20 has higher thermal conductivity than, for example, air, it has high heat dissipation properties, which allows the junction temperature (temperature of the active layer 104) to be instantly stabilized, further suppressing jitter. This leads to further stabilization of pulsed light emission. In particular, in the case of PCSEL, which has a large light-emitting area and voids in the photonic crystal layer 104, heat dissipation properties are important for suppressing jitter.

[0090] Furthermore, according to the light emitting device 1, since the saturable absorption regions SAR and the non-saturable absorption regions NSAR are arranged alternately in the radial direction of the first light emitting element section LE, it is possible to simultaneously emit multiple types of light emitting pulses with different parameters (e.g., pulse width, repetition frequency, pulse amplitude, etc.), and thus it is possible to accommodate multiple ranging modes with different ranging ranges, ranging speeds, and ranging accuracy.

[0091] 2. Light-emitting device according to example 2 of embodiment of the present technology> Fig. 17 is a partial cross-sectional view of a light-emitting device 2 according to example 2 of an embodiment of the present technology. Fig. 18 is a schematic plan view of the light-emitting device 2 according to example 2 of an embodiment of the present technology. Fig. 17 is a cross-sectional view of a portion of the light-emitting device 2 including a first light-emitting element unit LE and a dummy element unit DE adjacent to each other in the in-plane direction.

[0092] The light emitting device 2 has a configuration generally similar to that of the light emitting device 1 of Example 1, except that it has multiple (e.g., four) photonic crystal surface light emitting elements 10 and the mounting substrate 35 has first and second drive substrates 30, 40, as shown in Figures 17 and 18 as an example.

[0093] As an example, the light-emitting device 2 includes a light-emitting element assembly array LEA including a plurality of (e.g., four) first light-emitting element elements LE arranged two-dimensionally, and a pair of dummy element elements DE sandwiching the light-emitting element assembly array LEA in the in-plane direction (see FIG. 18 ). Each dummy element element DE is provided in common to the two light-emitting element elements LE adjacent to the dummy element element DE. In the light-emitting element assembly array LEA, each first light-emitting element element LE has an anode electrode 111 on a light-emitting mesa LM and shares the substrate 101, AR film 114, and first contact layer 102. In other words, the light-emitting element assembly array LEA has an electrode layout with independent anodes and a common cathode, and each first light-emitting element element LE can be driven independently.

[0094] As an example, the first drive substrate 30 includes a semiconductor substrate 31 and a first driver provided on the semiconductor substrate 31 and capable of driving the photonic crystal surface light emitting device 10 with high power. The first driver has an nMOS. Note that the first driver may have a pMOS instead of the nMOS. The semiconductor substrate 31 may be the same as the semiconductor substrate 21.

[0095] As an example, the second drive substrate 40 includes a semiconductor substrate 41 and a second driver provided on the semiconductor substrate 41 and capable of driving the photonic crystal surface light emitting device 10 at high speed. The second driver has multiple (e.g., two) nMOSs. Note that the second driver may have a pMOS instead of the nMOSs. The semiconductor substrate 41 may be the same as the semiconductor substrate 21.

[0096] As an example, the first and second drive substrates 30, 40 are stacked on top of each other. Here, the second drive substrate 40 is disposed between the first drive substrate 30 and the photonic crystal surface light emitting element 10. This allows the photonic crystal surface light emitting element 10 and the second drive substrate 40 to be placed close to each other, thereby reducing the impedance between the photonic crystal surface light emitting element 10 and the second drive substrate 40, and enabling the photonic crystal surface light emitting element 10 to be driven at a higher speed.

[0097] As an example, the first light-emitting element unit LE has an anode electrode 111 arranged on the mounting substrate 35 side connected to the source of the nMOS of the first driver of the first drive substrate 30 via a via 43 penetrating the second drive substrate 40 and a first bump B1-1, and also connected to the source of each nMOS of the second driver of the second drive substrate 40 via another first bump B1-2. The drain of the nMOS of the first driver is connected to the cathode of the current source of the first driver, as an example. The drain of each nMOS of the second driver is connected to the cathode of the current source of the second driver, as an example.

[0098] As an example, the nMOS of the first driver, the via 43, and the first bump B1-1 are arranged at positions overlapping the first non-saturable absorption region NSAR1 of the first light-emitting element component LE in plan view.

[0099] As an example, the two nMOSs of the second driver and the other first bump B1-2 are arranged at positions overlapping the first saturable absorption region SAR1 of the first light-emitting element unit LE in plan view.

[0100] As an example, the cathode wiring 113 is connected to the cathode of the current source of the first driver via the second bump B2, the cathode terminal 42b of the second drive substrate 40, the bonding wire BW, and the cathode terminal 32 of the first drive substrate 30, and is also connected to the cathode of the current source of the second driver via the second bump B2 and the cathode terminal 42b of the second drive substrate 40. The bonding wire BW is made of, for example, Au, Ag, Cu, or Al.

[0101] The first driver, for example, has an nMOS and a current source (e.g., a variable current source) whose drain and anode are connected and capable of supplying a large current. The second driver, for example, has, as each nMOS, a high-speed switching nMOS capable of generating current pulses at high speed, and a current source (e.g., a variable current source) whose drain and anode are connected and capable of supplying a small current.

[0102] 19, in the light emitting device 2, a first driver capable of high power driving is driven to apply a high output current pulse to the first light emitting element unit LE to accumulate energy, and before the applied current value reaches the threshold current Ith, a second driver capable of high speed driving is driven to apply a low output current pulse to the first light emitting element unit LE at high speed, thereby making it possible to make the applied current value exceed the threshold current Ith and kick-start laser oscillation, thereby further reducing jitter.

[0103] According to the light emitting device 2, it is possible to provide a light emitting device that can emit desired pulsed light more stably.

[0104] 3. Light-emitting device according to Example 3 of an embodiment of the present technology> Fig. 20 is a partial cross-sectional view of a light-emitting device 3 according to Example 3 of an embodiment of the present technology. Fig. 21 is a schematic plan view of the light-emitting device 3 according to Example 3 of an embodiment of the present technology. Fig. 22 is a diagram for explaining a function of the light-emitting device 3 of Fig. 20 .

[0105] As an example, as shown in Figures 20 and 21, the light emitting device 3 has a configuration generally similar to that of the light emitting device 1 of Example 1, except that the photonic crystal surface light emitting element 12 includes, in addition to the first light emitting element element LE, a second light emitting element element LE' that is spaced apart from the first light emitting element element LE1 in the in-plane direction and does not have a saturable absorption region SAR.

[0106] The light-emitting device 3 includes a photonic crystal surface light-emitting element 12 having a light-emitting element array LEA in which a plurality of (e.g., two) first light-emitting element elements LE and a plurality of (e.g., two) second light-emitting element elements LE' are two-dimensionally arranged, and a pair of dummy element elements DE sandwiching the light-emitting element array LEA in the in-plane direction (see FIG. 21 ). Each dummy element element DE is provided in common with two light-emitting element elements adjacent to the dummy element element DE. In the light-emitting element array LEA, each light-emitting element element has an anode electrode 111 on the light-emitting mesa and shares the substrate 101, AR film 114, and first contact layer 102 (see FIG. 20 ). In other words, the light-emitting element array LEA has an electrode layout with independent anodes and a common cathode, allowing each light-emitting element element to be driven independently.

[0107] In the light emitting device 3, the light emitting element array LEA has, as an example, first and second light emitting element units LE, LE' arranged in a matrix in an in-plane direction in a staggered manner (see FIG. 21). Note that the arrangement of the first and second light emitting element units LE, LE' does not have to be staggered.

[0108] In the light emitting device 3, the drive substrate serving as the mounting substrate 20 has two nMOSs corresponding to the first and second light emitting element units LE and LE', respectively, each of whose sources is connected to the anode electrode 111 of the corresponding light emitting element unit.

[0109] In the light emitting device 3, the first and second light emitting element units LE and LE' can be selectively oscillated by selectively driving two nMOSs. This makes it possible to switch between pulsed light emission with a pulse width on the order of about 10 ps and pulsed light emission with a pulse width on the order of about 100 ps (see FIG. 22).

[0110] According to the light emitting device 3, since it has a first light emitting element LE having a saturable absorption region SAR and a second light emitting element LE' not having a saturable absorption region SAR, it is possible to selectively emit pulsed light in accordance with various distance measurement modes that differ in at least one of the required distance measurement range, distance measurement speed, and distance measurement accuracy.

[0111] 23 is a partial cross-sectional view of a light emitting device 4 according to a fourth example of an embodiment of the present technology. FIG. 24 is a plan view of a photonic crystal surface light emitting element 13 of a light emitting device 4 according to a fourth example of an embodiment of the present technology. FIG. 25 is a schematic plan view of a light emitting device 4 according to a fourth example of an embodiment of the present technology. FIG. 26 is a diagram illustrating a first configuration example of an anode electrode 111 of the light emitting device 4 of FIG. 23. FIG. 27 is a diagram illustrating a second configuration example of an anode electrode 111 of the light emitting device 4 of FIG. 23.

[0112] As an example, as shown in Figures 23 and 24, the light emitting device 4 has a configuration that is generally similar to that of the light emitting device 1 of Example 1, except that the driver of the drive board serving as the mounting board 20 includes a first switching element 23a for emitting long pulses and multiple (e.g., two) second switching elements 23b for emitting short pulses.

[0113] The first switching element 23a is, for example, a current modulation nMOS that performs a current modulation operation. The second switching element 23b is, for example, a Q-switch nMOS that performs a Q-switch operation. The multiple second switching elements 23b can be driven in parallel (synchronously).

[0114] In the light-emitting device 4, the anode electrode 111 includes a first electrode portion 111a provided on the central portion of the first light-emitting element component LE having the first non-saturable absorption region NSAR1 and connected to the first switching element 23a via a first bump B1-1, and a second electrode portion 111b provided on the periphery of the first light-emitting element component LE having the first saturable absorption region SAR1 and connected to the second switching element 23b via another first bump B1-2. The second electrode portion 111b surrounds the first electrode portion 111a (see FIG. 26). Note that the second electrode portion 111b may have multiple portions arranged to surround the first electrode portion 111a (see FIG. 27).

[0115] The first switching element 23 a is electrically connected to the center of the first light-emitting element component LE, which has the first non-saturable absorption region NSAR1. More specifically, the source of the current modulation nMOS serving as the first switching element 23 a is connected to the center of the first light-emitting element component LE via the anode terminal 22 a of the mounting substrate 20, a first bump B1-1 located at a position corresponding to the center of the first light-emitting element component LE, and a first electrode portion 111 a of the anode electrode 111.

[0116] The second switching element 23b is electrically connected to the peripheral portion (portion surrounding the central portion) of the first light-emitting element component LE, which has the first saturable absorption region SAR1. More specifically, the source of the Q-switch nMOS serving as the second switching element 23b is connected to the peripheral portion of the first light-emitting element component LE via the anode terminal 22a of the mounting substrate 20, another first bump B1-2 located at a position corresponding to the peripheral portion of the first light-emitting element component LE, and the second electrode portion 111b of the anode electrode 111.

[0117] In the light emitting device 4, only the current modulation nMOS is driven when it is desired to emit pulsed light with a pulse width of, for example, the order of 100 ps. When the current modulation nMOS is driven, the current passes mainly through the center of the first light emitting element section LE, so that light resonates within the photonic crystal layer 106 in the center, but since there is no saturable absorption region in the center, oscillation occurs on the order of 100 ps.

[0118] In the light-emitting device 4, when it is desired to emit pulsed light with a pulse width on the order of, for example, 10 ps, ​​only the multiple Q-switch nMOSs are driven (parallel drive). Parallel drive results in a sharp rise in the current pulses generated. When the Q-switch nMOSs are driven, the current passes mainly through the peripheral portion of the first light-emitting element section LE, causing light to resonate within the photonic crystal layer 106 in this peripheral portion. However, since the peripheral portion contains a saturable absorption region, the Q-switch operates and oscillates on the order of 10 ps.

[0119] According to the light-emitting device 4, the first and second switching elements 23a, 23b can be selectively driven, thereby enabling selective oscillation in the first non-saturable absorption region NSAR1 and the first saturable absorption region SAR1 of the first light-emitting element unit LE, and therefore long-pulse light and short-pulse light can be selectively output from the single first light-emitting element unit LE.

[0120] 28 is a partial cross-sectional view of a light emitting device 5 according to Example 5 of an embodiment of the present technology. Fig. 29 is a schematic plan view of a light emitting device 5 according to Example 5 of an embodiment of the present technology.

[0121] As shown in FIGS. 28 and 29, the light emitting device 5 has a configuration generally similar to that of the light emitting device 3 according to the third embodiment, except that the mounting substrate 35 has first and second drive substrates 30 and 40 .

[0122] The first drive substrate 30 includes a semiconductor substrate 31 and a first driver provided on the semiconductor substrate 31 and capable of driving the photonic crystal surface light emitting device 10 with high power. The first driver has an nMOS. Note that the first driver may have a pMOS instead of the nMOS. The semiconductor substrate 31 may be the same as the semiconductor substrate 21.

[0123] The second drive substrate 40 includes a semiconductor substrate 41 and a second driver provided on the semiconductor substrate 41 and capable of driving the photonic crystal surface light emitting device 10 at high speed. The second driver has multiple (e.g., two) nMOSs. The second driver may have a pMOS instead of the nMOSs. The semiconductor substrate 41 may be the same as the semiconductor substrate 21.

[0124] As an example, the first and second drive substrates 30, 40 are stacked on top of each other. Here, the second drive substrate 40 is disposed between the first drive substrate 30 and the photonic crystal surface light emitting element 10. This allows the photonic crystal surface light emitting element 10 and the second drive substrate 40 to be placed close to each other, thereby reducing the impedance between the photonic crystal surface light emitting element 10 and the second drive substrate 40, and enabling the photonic crystal surface light emitting element 10 to be driven at a higher speed.

[0125] The first light-emitting element unit LE has an anode electrode 111 arranged on the mounting substrate 35 side, which is connected to the source of the nMOS of the first driver of the first drive substrate 30 via a via 43 that penetrates the second drive substrate 40 and a first bump B1-1, and is also connected to the source of the nMOS of the second driver of the second drive substrate 40 via another first bump B1-2.

[0126] As an example, the nMOS of the first driver, the via 43, and the first bump B1-1 are arranged at positions overlapping the first non-saturable absorption region NSAR1 of the first light-emitting element component LE in plan view.

[0127] In the second light emitting element unit LE', the anode electrode 111 arranged on the mounting substrate 35 side is connected to the source of each nMOS of the second driver of the second drive substrate 40 via another first bump B1-2.

[0128] As an example, the two nMOSs of the second driver and the other first bump B1-2 are arranged at positions overlapping the first saturable absorption region SAR1 of the first light-emitting element unit LE in plan view.

[0129] The cathode wiring 113 is connected to the cathode terminal of the current source of the first driver via the second bump B2, the cathode terminal 42b of the second drive substrate 40, the bonding wire BW, and the cathode terminal 32 of the first drive substrate 30, and is also connected to the cathode terminal of the current source of the second driver via the second bump B2 and the cathode terminal 42b of the second drive substrate 40.

[0130] The first driver, for example, has an nMOS and a current source (e.g., a variable current source) whose drain and anode are connected and capable of supplying a large current. The second driver, for example, has, as each nMOS, a high-speed switching nMOS capable of generating current pulses at high speed, and a current source (e.g., a variable current source) whose drain and anode are connected and capable of supplying a small current.

[0131] In the light emitting device 5, the first driver capable of high power driving is driven to apply a high output current pulse to the first light emitting element unit LE to accumulate energy, and before the applied current value reaches the threshold current Ith, the second driver capable of high speed driving is driven to apply a low output current pulse to the first light emitting element unit LE at high speed, thereby making the applied current value exceed the threshold current Ith and kick-starting laser oscillation. This makes it possible to further reduce jitter.

[0132] According to the light emitting device 5, it is possible to obtain both the effects of the light emitting device 2 according to the second embodiment and the effects of the light emitting device 3 according to the third embodiment.

[0133] 6. Light-emitting device according to Example 6 of an embodiment of the present technology FIG. 30 is a partial cross-sectional view of a light-emitting device 6 according to Example 6 of an embodiment of the present technology.

[0134] As shown in FIG. 30, the light emitting device 6 has a configuration that is generally similar to that of the light emitting device 4 according to the fourth embodiment, except that a mounting substrate 35 has first and second drive substrates 30 and 40 .

[0135] In the light emitting device 6, the first drive substrate 30 has a current modulation nMOS, and the second drive substrate 40 has a plurality of (for example, two) Q switch nMOSs.

[0136] According to the light emitting device 6, it is possible to obtain both the effects of the light emitting device 2 according to the second embodiment and the effects of the light emitting device 4 according to the fourth embodiment.

[0137] 31 is a partial cross-sectional view of a light emitting device 7 according to Example 7 of an embodiment of the present technology. Fig. 32 is a plan view (view from the mounting substrate 20 side) of a photonic crystal surface light emitting element 14 of the light emitting device 7 according to Example 7 of an embodiment of the present technology.

[0138] As shown in Figures 31 and 32, the light emitting device 7 has a configuration generally similar to that of the light emitting device 1 of Example 1, except that the light emitting element section LE of the photonic crystal surface light emitting element 14 has a mesare-less structure.

[0139] In the light-emitting device 7, a first light-emitting element component LE having a mesare-less structure and a dummy element component DE are separated by an isolation trench IT. One of the two opposing side surfaces of the isolation trench IT is the side surface of the first light-emitting element component LE on the dummy element component DE side, and the other side surface is the side surface of the dummy element component DE on the first light-emitting element component LE side. The isolation trench IT may have an interrupted portion (discontinuous portion).

[0140] Two opposing side surfaces of the separation trench IT, the surface of the first light-emitting element unit LE facing the mounting substrate 20, and the surface of the dummy element unit DE facing the mounting substrate 20 are covered with an insulating film 110. A cathode electrode 112 is provided on the bottom surface of the separation trench IT (the upper surface of the first contact layer 102). A cathode wiring 113 is provided in contact with the cathode electrode 112 within the separation trench IT, and is provided so as to cover the two opposing side surfaces of the separation trench IT and the insulating film 110 provided on the surface of the dummy element unit DE facing the mounting substrate 20.

[0141] According to the light emitting device 7, the same effects as those of the light emitting device 1 according to the first embodiment can be obtained.

[0142] 8. Light-emitting device according to example 8 of embodiment of the present technology> FIG. 33 is a cross-sectional view of a light-emitting device 8 according to example 8 of an embodiment of the present technology.

[0143] As shown in Figure 33, the light emitting device 8 has a configuration that is generally similar to that of the light emitting device 1 of Example 1, except that the photonic crystal surface emitting element 15 is a surface-emitting photonic crystal surface emitting laser and is mounted on the mounting substrate 20 in a junction-up position.

[0144] The photonic crystal surface light emitting device 15 has an intra-cavity structure.

[0145] In the photonic crystal surface light emitting element 15, a first contact layer 102, a reflector 108 (e.g., an n-type semiconductor multilayer reflector), a first cladding layer 103, an active layer 104, a photonic crystal layer 106, a second cladding layer 107, and a second contact layer 109 are stacked in this order on a substrate 101.

[0146] Here, the light emitting mesa LM is configured by a reflecting mirror 108 (for example, an n-type semiconductor multilayer film reflecting mirror), a first cladding layer 103, an active layer 104, a photonic crystal layer 106, a second cladding layer 107, and a second contact layer 109. The upper surface of the light emitting mesa LM (more specifically, the upper surface of the second contact layer 109) serves as the emission surface.

[0147] In the photonic crystal surface light emitting element 15, the anode electrode 111 provided on the second contact layer 109 is connected to the anode terminal 22a of the mounting substrate 220 via a first bonding wire BW1, and the cathode electrode 112 provided on the first contact layer 102 is connected to the cathode terminal 22b of the mounting substrate 20 via a second bonding wire BW2. Each bonding wire is made of, for example, Au, Ag, Cu, Al, or the like. Here, multiple (e.g., two) nMOSs are respectively connected to multiple (e.g., two) anode terminals 22a of the mounting substrate 20. By driving the two nMOSs in parallel, a current pulse with a sharp rise can be supplied to the light emitting element unit LE.

[0148] According to the light emitting device 8, although the effect is somewhat inferior to that of the light emitting device 1 of Example 1 in which the photonic crystal surface emitting element 10 is mounted junction-down on the mounting substrate 20, it is possible to provide a light emitting device 8 in which a surface-emitting photonic crystal surface emitting element 15 is mounted on the mounting substrate 20, which can instantly and stably emit the desired pulsed light.

[0149] 9. Light Receiving and Emitting Device According to Ninth Example of Embodiment of the Present Technology FIG. 34 is a cross-sectional view of a light receiving and emitting device 9 according to a ninth example of an embodiment of the present technology.

[0150] As shown in Figure 34, the light receiving and emitting device 9 has a configuration that is generally similar to that of the light emitting device 1 of Example 1, except that, as an example, a light receiving element 39 is semi-embedded in a part of the semiconductor substrate 21 of the mounting substrate 20 that does not face the photonic crystal surface light emitting element 10.

[0151] The light receiving element 39 may be, for example, a PIN photodiode, a PN photodiode, an avalanche photodiode, or the like.

[0152] In the light receiving and emitting device 9 , the light emitted from the photonic crystal surface light emitting element 10 and reflected by an object is received by the light receiving element 39 .

[0153] The light receiving and emitting device 9 may have, for example, a TOF (Time Of Flight) calculation circuit connected to the photonic crystal surface light emitting element 10 and the light receiving element 39 provided on the semiconductor substrate 21. In this case, the light receiving and emitting device 9 can essentially constitute a distance measuring device.

[0154] 10. Modifications of the present technology

[0155] The present technology is not limited to the examples of the above-described embodiment, and various modifications are possible.

[0156] For example, in each of the above embodiments, the first light-emitting element component LE has a non-saturable absorption region NSAR in the center and at least a saturable absorption region SAR in the peripheral region, but the first light-emitting element component LE may have a saturable absorption region SAR in the center and at least a non-saturable absorption region NSAR in the peripheral region. Furthermore, the first light-emitting element component LE may have a saturable absorption region SAR over the entire region in a plan view. The positions, sizes, and numbers of the saturable absorption regions SAR and the non-saturable absorption regions NSAR can be changed as appropriate.

[0157] The saturable absorption region SAR is preferably provided at least in the second contact layer 109 .

[0158] The saturable absorption region SAR is preferably provided in at least the photonic crystal layer 106 and / or the active layer 104 .

[0159] The saturable absorption region SAR is preferably provided at least in the second cladding layer 107 .

[0160] The saturable absorber region SAR may be provided at least in the first cladding layer 103 .

[0161] The saturable absorption region SAR may be provided at least in the first contact layer 102 .

[0162] It is preferable that the saturable absorption region SAR is provided at least on the reflecting mirror 108 .

[0163] The saturable absorption region SAR may be provided at least in the substrate 101 .

[0164] For example, in each of the above examples, a photonic crystal surface-emitting laser was used as an example of a photonic crystal surface-emitting element of a light-emitting device according to the present technology, but the present technology can also be applied to, for example, a photonic crystal light-emitting diode (resonant or non-resonant type).

[0165] The pulse width of the light emission pulse may be adjusted by varying the effect of the saturable absorber in the saturable absorption region by adjusting the intensity of the excitation current.

[0166] For example, in each of the above embodiments, a semiconductor multilayer film reflector is used as the reflector, but this is not limited to this. For example, a dielectric multilayer film reflector or a hybrid mirror including at least two of a semiconductor multilayer film reflector, a dielectric multilayer film reflector, and a metal reflector may also be used.

[0167] For example, in each of the above embodiments, the photonic crystal surface light-emitting element is made of a material that is lattice-matched to GaAs (GaAs-based compound semiconductor), but this is not limited thereto, and for example, a material that is lattice-matched to InP (InP-based compound semiconductor) or a material that is lattice-matched to GaN (GaN-based compound semiconductor) may also be used.

[0168] For example, the conductivity types of the layers on both sides (upper and lower sides) of the active layer 104 of the photonic crystal surface light emitting device according to each of the above embodiments may be reversed. In this case, reference numeral 112 is the anode electrode, reference numeral 113 is the anode wiring, and reference numeral 111 is the cathode electrode.

[0169] At least one of the first and second contact layers 102 and 109 may not be provided.

[0170] One of the first and second cladding layers 103 and 107 may not be provided. In this case, the semiconductor multilayer film reflecting mirror serving as the reflecting mirror 108 may also serve as the one of the cladding layers.

[0171] The reflecting mirror 108 may not be provided.

[0172] The dummy element portion DE does not necessarily have to be provided.

[0173] For example, in each of the above embodiments, a MOSFET is used as the switching element of the laser driver, but other field effect transistors such as a junction FET may also be used, or a bipolar transistor may also be used.

[0174] Parts of the configurations of the light emitting devices of the above-described embodiments may be combined within the scope of not mutually contradicting each other.

[0175] For example, the photonic crystal surface light emitting device according to the present technology may have a multi-junction structure in which two or more active layers 104 are stacked. In this case, too, it is preferable to dispose a tunnel junction layer between the active layers 104 adjacent to each other in the stacking direction.

[0176] In each of the above embodiments, the material, conductivity type, thickness, width, value, shape, size, etc. of each layer constituting the photonic crystal surface light emitting device and the mounting substrate can be changed as appropriate within the range in which the photonic crystal surface light emitting device and the mounting substrate function.

[0177] 11. Application Examples to Electronic Devices The technology according to the present disclosure (the present technology) can be applied to various products (electronic devices). For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, or a low-power device (for example, a smartphone, a smartwatch, a tablet, a mouse, a laptop computer, or the like), or as a communication device.

[0178] The light emitting device according to the present technology can also be applied as a light source for devices that form or display images using laser light (for example, laser printers, laser copiers, projectors, head-mounted displays, head-up displays, etc.).

[0179] 12. Example of Application of Light Emitting Device to Distance Measuring Device An application example of the light emitting device 1 according to the first embodiment will be described below.

[0180] 35 illustrates an example of a schematic configuration of a distance measurement device 1000 (distance measuring device) including a light emitting device 1, as an example of an electronic device according to the present technology. The distance measurement device 1000 measures the distance to a subject S by a TOF (Time Of Flight) method. The distance measurement device 1000 includes the light emitting device 1. The distance measurement device 1000 includes, for example, the light emitting device 1, a light receiving device 125, lenses 128 and 130, a signal processing unit 145, a control unit 155, a display unit 165, and a storage unit 170.

[0181] The light-receiving device 125 receives light emitted from the light-emitting device 1 and reflected by the specimen S (object). In other words, the light-receiving device 125 detects the light reflected by the specimen S. The lens elements constituting the lens 128 are lenses, such as collimating lenses, that collimate the light emitted from the light-emitting device 1. Because the light emitted from the light-emitting device 1 is inherently collimated, the minimum number of lenses 128 is sufficient to achieve the desired beam quality, and fewer lenses are required than in conventional surface-emitting lasers (e.g., VCSELs). Another feature of the light-emitting device 1 is its ability to emit multiple beams of light in desired directions, roughly equivalent to a diffraction grating. In typical usage, this function is included in the external lens 128. The lens 130 is a lens, such as a focusing lens, that focuses the light reflected by the specimen S and guides it to the light-receiving device 125.

[0182] The signal processing unit 145 is a circuit for generating a signal corresponding to the difference between the signal input from the light-receiving device 125 and the reference signal input from the control unit 155. The control unit 155 is configured to include, for example, a time-to-digital converter (TDC). The reference signal may be a signal input from the control unit 155 or an output signal from a detection unit that directly detects the output of the light-emitting device 1. The control unit 155 is, for example, a processor that controls the light-emitting device 1, the light-receiving device 125, the signal processing unit 145, the display unit 165, and the storage unit 170. The control unit 155 is a circuit that measures the distance to the subject S based on the signal generated by the signal processing unit 145. The control unit 155 generates a video signal for displaying information about the distance to the subject S and outputs it to the display unit 165. The display unit 165 displays the information about the distance to the subject S based on the video signal input from the control unit 155. The control unit 155 stores the information about the distance to the subject S in the storage unit 170.

[0183] In this application example, instead of the light emitting device 1, any of the light emitting devices 2, 3, 4, 5, 67, and 8 and the light receiving / emitting device 9 (light receiving device 125 is not necessary) can be applied to the distance measurement device 1000.

[0184] 13. Example in which distance measuring device is mounted on a moving body> FIG. 36 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving body control system to which the technology according to the present disclosure can be applied.

[0185] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 36, 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. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0186] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0187] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0188] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, a distance measurement device 12031 is connected to the outside-vehicle information detection unit 12030. The distance measurement device 12031 includes the above-described distance measurement device 1000. The outside-vehicle information detection unit 12030 causes the distance measurement device 12031 to measure the distance to an object outside the vehicle (subject S) and acquires the distance data obtained thereby. The outside-vehicle information detection unit 12030 may perform object detection processing for people, cars, obstacles, signs, etc. based on the acquired distance data.

[0189] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0190] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0191] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0192] Furthermore, 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. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0193] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 36, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0194] FIG. 37 is a diagram showing an example of the installation position of the distance measurement device 12031.

[0195] In FIG. 37, a vehicle 12100 has distance measurement devices 12101, 12102, 12103, 12104, and 12105 as a distance measurement device 12031.

[0196] Distance measuring devices 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 cabin of vehicle 12100. Distance measuring device 12101 provided on the front nose and distance measuring device 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire data ahead of vehicle 12100. Distance measuring devices 12102 and 12103 provided on the side mirrors mainly acquire data on the sides of vehicle 12100. Distance measuring device 12104 provided on the rear bumper or back door mainly acquires data behind vehicle 12100. The forward data acquired by distance measuring devices 12101 and 12105 is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, etc.

[0197] 37 shows an example of the detection ranges of the distance measuring devices 12101 to 12104. Detection range 12111 indicates the detection range of the distance measuring device 12101 provided on the front nose, detection ranges 12112 and 12113 indicate the detection ranges of the distance measuring devices 12102 and 12103 provided on the side mirrors, respectively, and detection range 12114 indicates the detection range of the distance measuring device 12104 provided on the rear bumper or back door.

[0198] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the detection ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0199] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0200] The above describes an example of a mobile object control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the distance measurement device 12031 of the above-described configuration.

[0201] The present technology can also be configured as follows: (1) A light-emitting device comprising: a photonic crystal surface light-emitting element including at least one light-emitting element portion having an active layer and a photonic crystal layer; and a mounting substrate on which the photonic crystal surface light-emitting element is mounted, wherein the at least one light-emitting element portion includes a first light-emitting element portion that is the light-emitting element portion provided with a saturable absorption region. (2) The light-emitting device according to (1), wherein the light-emitting element portion is bonded to the mounting substrate via a bump. (3) The light-emitting device according to (1) or (2), wherein the mounting substrate includes at least one drive substrate having a driver that drives the photonic crystal surface light-emitting element. (4) The light-emitting device according to (3), wherein the driver has a plurality of switching elements. (5) The light-emitting device according to (4), wherein the plurality of switching elements include at least two switching elements connected in parallel to the first light-emitting element portion. (6) The light-emitting device according to any one of (1) to (5), wherein the photonic crystal surface light-emitting element includes a substrate, the light-emitting element portion is provided on the substrate, and the photonic crystal surface light-emitting element emits light to the side of the substrate opposite the light-emitting element portion. (7) The light-emitting device according to any one of (1) to (6), wherein the first light-emitting element portion has a non-saturable absorption region that is not the saturable absorption region and is adjacent to the saturable absorption region in-plane. (8) The light-emitting device according to (7), wherein the saturable absorption region and the non-saturable absorption region are aligned in the radial direction of the first light-emitting element portion. (9) The light-emitting device according to (7) or (8), wherein the saturable absorption region and the non-saturable absorption region are aligned alternately in the radial direction of the first light-emitting element portion. (10) The light-emitting device according to any one of (7) to (9), wherein the non-saturable absorption region is present in at least the center of the first light-emitting element portion in a planar view. (11) The light emitting device according to any one of (1) to (10), wherein the saturable absorption region is present at least in the periphery of the first light emitting element component in a planar view. (12) The light emitting device according to any one of (1) to (11), wherein the mounting substrate includes: a first drive substrate having a first driver capable of driving the photonic crystal surface light emitting element with high power; and a second drive substrate having a second driver capable of driving the photonic crystal surface light emitting element at high speed.(13) The light emitting device according to (12), wherein the second drive substrate is disposed between the first drive substrate and the photonic crystal surface light emitting element. (14) The light emitting device according to (13), wherein the first light emitting element section has a first electrode on the mounting substrate side, and the first electrode is connected to the first driver via a via and a bump penetrating the second drive substrate, and is connected to the second driver via another bump. (15) The light emitting device according to (13) or (14), wherein the photonic crystal surface light emitting element includes a dummy element section disposed spaced apart from the light emitting element section in an in-plane direction, and the dummy element section has a second electrode on the mounting substrate side that is electrically connected to the light emitting element section, and the second electrode is connected to the first driver via a bonding wire, and is connected to the second driver via a bump. (16) The light-emitting device according to any one of (1) to (15), wherein the at least one light-emitting element component includes a second light-emitting element component spaced apart from the first light-emitting element component in an in-plane direction and not including the saturable absorption region. (17) The light-emitting device according to (16), wherein the mounting substrate comprises: a first drive substrate including a first driver capable of driving the first light-emitting element component with high power; and a second drive substrate including a second driver capable of driving at least the first light-emitting element component of the first and second light-emitting element components at high speed. (18) The light-emitting device according to (17), wherein the second drive substrate is disposed between the first drive substrate and the photonic crystal surface light-emitting element. (19) The light-emitting device according to (17) or (18), wherein the first light-emitting element component has a first electrode on the mounting substrate side, and the first electrode is connected to the first driver via a via and a bump penetrating the second drive substrate, and is connected to the second driver via another bump. (20) A light-emitting device described in any one of (17) to (18), wherein the photonic crystal surface light-emitting element includes a dummy element portion arranged at a distance in the in-plane direction from the light-emitting element portion, the dummy element portion has a second electrode electrically connected to the light-emitting element portion on the mounting substrate side, and the second electrode is connected to the first driver via a bonding wire and to the second driver via a bump.(21) The light-emitting device according to any one of (1) to (20), wherein the mounting substrate has at least one driver that drives the first light-emitting element component, and the driver includes: a first switching element for long-pulse emission; and a second switching element for short-pulse emission. (22) The light-emitting device according to (21), wherein the first switching element performs a current modulation operation, and the second switching element performs a Q-switching operation. (23) The light-emitting device according to (21), wherein the first light-emitting element component has a non-saturable absorption region that is not the saturable absorption region and is adjacent to the saturable absorption region in-plane, the non-saturable absorption region being present in at least a central portion of the first light-emitting element component in a planar view, the saturable absorption region being present in at least a peripheral portion of the first light-emitting element component in a planar view, the first switching element being electrically connected to the central portion, and the second switching element being electrically connected to the peripheral portion. (24) The light-emitting device according to (23), wherein the first light-emitting element component has an electrode on the mounting substrate side that is electrically connected to the driver, the electrode comprising: a first electrode component provided on the central portion and connected to the first switching element via a bump; and a second electrode component provided on the peripheral portion and connected to the second switching element via another bump. (25) The light-emitting device according to (24), wherein the second electrode component surrounds the first electrode component. (26) The light-emitting device according to (24) or (25), wherein the second electrode component has a plurality of portions arranged to surround the first electrode component. (27) The light-emitting device according to any one of (21) to (26), wherein the at least one driver comprises: a first driver having the first switching element and capable of being driven with high power; and a second driver having the second switching element and capable of being driven at high speed. (28) The light emitting device according to (27), wherein a second drive substrate having the second driver is disposed between a first drive substrate having the first driver and the photonic crystal surface light emitting element.(29) The light-emitting device according to (28), wherein the first light-emitting element component has a first electrode on the mounting substrate side, the first electrode being connected to the first driver via a via and a bump penetrating the second drive substrate, and connected to the second driver via another bump. (30) The light-emitting device according to (28) or (29), wherein the photonic crystal surface light-emitting element includes a dummy element component arranged spaced apart from the light-emitting element component in an in-plane direction, the dummy element component having a second electrode on the mounting substrate side electrically connected to the light-emitting element component, the second electrode being connected to the first driver via a bonding wire, and connected to the second driver via a bump. (31) The light-emitting device according to any one of (1) to (30), wherein the saturable absorption region is provided at least in the photonic crystal layer and / or the active layer. (32) The light emitting device according to any one of (1) to (31), wherein the first light emitting element component has first and second clad layers sandwiching a light emitting element including the photonic crystal layer and the active layer, and the saturable absorption region is provided in at least the first clad layer and / or the second clad layer. (33) The light emitting device according to any one of (1) to (32), wherein the first light emitting element component has a reflector on the mounting substrate side of the light emitting element including the photonic crystal layer and the active layer, and the saturable absorption region is provided in at least the reflector. (34) A light emitting and receiving device comprising: a photonic crystal surface light emitting element including at least one light emitting element component having an active layer and a photonic crystal layer, and a mounting substrate on which the photonic crystal surface light emitting element is mounted, wherein at least one of the light emitting element components includes a first light emitting element component provided with a saturable absorption region; and a light receiving element that receives light emitted from the light emitting device and reflected by an object. (35) An electronic device comprising a light-emitting device, the light-emitting device including: a photonic crystal surface light-emitting element including at least one light-emitting element portion having an active layer and a photonic crystal layer; and a mounting substrate on which the photonic crystal surface light-emitting element is mounted, wherein at least one of the light-emitting element portions includes a first light-emitting element portion that is the light-emitting element portion provided with a saturable absorption region.

[0202] 1, 2, 3, 4, 5, 6, 7, 8: Light emitting device 10, 11, 12, 13, 14, 15: Photonic crystal surface light emitting element 20, 35: Mounting substrate 23a: First switching element 23b: Second switching element 30: First drive substrate 40: Second drive substrate 43: Via BW: Bonding wire 101: Substrate 103: First cladding layer 104: Active layer 106: Photonic crystal layer 107: Second cladding layer 108: Reflector 111: Anode electrode (first electrode) 113: Cathode wiring (part of which is second electrode) LE: Light emitting element portion, first light emitting element portion LE': Second light emitting element portion DE: Dummy element portion B1, B1-1: First bump (bump) B1-2: Another first bump (bump) B2: Second bump (bump) SAR, SAR1, SAR2: Saturable absorption region NSAR, NSAR1, NSAR2: Non-saturable absorption region

Claims

1. A light emitting device comprising: a photonic crystal surface light emitting element including at least one light emitting element component having an active layer and a photonic crystal layer; and a mounting substrate on which the photonic crystal surface light emitting element is mounted, wherein at least one of the light emitting element components includes a first light emitting element component that is the light emitting element component provided with a saturable absorption region.

2. The light emitting device according to claim 1, wherein the light emitting element section is bonded to the mounting substrate via bumps.

3. The light emitting device according to claim 1, wherein the mounting substrate includes at least one drive substrate having a driver for driving the photonic crystal surface light emitting element.

4. The light emitting device according to claim 3, wherein the driver has a plurality of switching elements.

5. The light emitting device according to claim 4, wherein said plurality of switching elements includes at least two switching elements connected in parallel to said first light emitting element portion.

6. The light-emitting device according to claim 1, wherein the photonic crystal surface light-emitting element includes a substrate, the light-emitting element section is provided on the substrate, and the photonic crystal surface light-emitting element emits light on the side of the substrate opposite to the light-emitting element section side.

7. The light emitting device according to claim 1, wherein said first light emitting element portion has a non-saturable absorbing region which is not said saturable absorbing region and is adjacent to said saturable absorbing region in the plane.

8. The light emitting device according to claim 7, wherein the saturable absorption region and the non-saturable absorption region are aligned in the radial direction of the first light emitting element portion.

9. The light emitting device according to claim 7, wherein the saturable absorption regions and the non-saturable absorption regions are alternately arranged in the radial direction of the first light emitting element portion.

10. The light emitting device according to claim 7, wherein the non-saturable absorption region is present at least in the center of the first light emitting element component in a plan view.

11. The light emitting device according to claim 1, wherein the saturable absorption region is present at least in the peripheral portion of the first light emitting element component in plan view.

12. The light-emitting device according to claim 1, wherein the mounting substrate includes: a first drive substrate having a first driver capable of driving the photonic crystal surface-emitting element with high power; and a second drive substrate having a second driver capable of driving the photonic crystal surface-emitting element at high speed.

13. The light emitting device according to claim 12, wherein the second drive substrate is disposed between the first drive substrate and the photonic crystal surface light emitting element.

14. The light-emitting device described in claim 13, wherein the first light-emitting element section has a first electrode on the mounting substrate side, and the first electrode is connected to the first driver through a via and a bump that penetrates the second drive substrate, and is connected to the second driver through another bump.

15. The light-emitting device described in claim 13, wherein the photonic crystal surface light-emitting element includes a dummy element portion arranged at a distance in the in-plane direction from the light-emitting element portion, the dummy element portion has a second electrode electrically connected to the light-emitting element portion on the mounting substrate side, and the second electrode is connected to the first driver via a bonding wire and to the second driver via a bump.

16. The light-emitting device according to claim 1, wherein the at least one light-emitting element component includes a second light-emitting element component that is spaced apart from the first light-emitting element component in the in-plane direction and does not have the saturable absorption region.

17. The light-emitting device described in claim 16, wherein the mounting substrate comprises: a first drive substrate including a first driver capable of driving the first light-emitting element portion with high power; and a second drive substrate including a second driver capable of driving at least the first light-emitting element portion of the first and second light-emitting element portions at high speed.

18. The light emitting device according to claim 17, wherein the second drive substrate is disposed between the first drive substrate and the photonic crystal surface light emitting element.

19. The light-emitting device described in claim 18, wherein the first light-emitting element section has a first electrode on the mounting substrate side, and the first electrode is connected to the first driver through a via and a bump that penetrates the second drive substrate, and is connected to the second driver through another bump.

20. The light-emitting device described in claim 18, wherein the photonic crystal surface light-emitting element includes a dummy element portion arranged at a distance in the in-plane direction from the light-emitting element portion, the dummy element portion having a second electrode electrically connected to the light-emitting element portion on the mounting substrate side, and the second electrode is connected to the first driver via a bonding wire and to the second driver via a bump.

21. The light emitting device according to claim 1, wherein the mounting substrate has at least one driver that drives the first light emitting element section, and the driver includes: a first switching element for long pulse emission; and a second switching element for short pulse emission.

22. The light emitting device according to claim 21, wherein the first switching element performs a current modulation operation, and the second switching element performs a Q-switch operation.

23. The light-emitting device described in claim 21, wherein the first light-emitting element portion has a non-saturable absorption region that is not the saturable absorption region and is adjacent to the saturable absorption region in the plane, the non-saturable absorption region is present in at least the central portion of the first light-emitting element portion in a planar view, the saturable absorption region is present in at least the peripheral portion of the first light-emitting element portion in a planar view, the first switching element is electrically connected to the central portion, and the second switching element is electrically connected to the peripheral portion.

24. A light-emitting device as described in claim 23, wherein the first light-emitting element portion has an electrode electrically connected to the driver on the mounting substrate side, the electrode having: a first electrode portion provided on the central portion and connected to the first switching element via a bump; and a second electrode portion provided on the peripheral portion and connected to the second switching element via another bump.

25. The light emitting device according to claim 24, wherein the second electrode portion surrounds the first electrode portion.

26. The light emitting device according to claim 24, wherein the second electrode portion has a plurality of portions arranged so as to surround the first electrode portion.

27. The light emitting device according to claim 21, wherein the at least one driver comprises: a first driver having the first switching element and capable of being driven with high power; and a second driver having the second switching element and capable of being driven at high speed.

28. The light emitting device according to claim 27, wherein a second drive substrate having the second driver is disposed between a first drive substrate having the first driver and the photonic crystal surface light emitting element.

29. A light-emitting device as described in claim 28, wherein the first light-emitting element section has a first electrode on the mounting substrate side, and the first electrode is connected to the first driver through a via and a bump that penetrates the second drive substrate, and is connected to the second driver through another bump.

30. The light-emitting device described in claim 28, wherein the photonic crystal surface light-emitting element includes a dummy element portion arranged at a distance in the in-plane direction from the light-emitting element portion, the dummy element portion having a second electrode electrically connected to the light-emitting element portion on the mounting substrate side, and the second electrode is connected to the first driver via a bonding wire and to the second driver via a bump.

31. The light-emitting device according to claim 1, wherein the saturable absorption region is provided in at least the photonic crystal layer and / or the active layer.

32. A light-emitting device as described in claim 1, wherein the first light-emitting element section has first and second clad layers sandwiching a light-emitting section including the photonic crystal layer and the active layer, and the saturable absorption region is provided in at least the first clad layer and / or the second clad layer.

33. The light-emitting device according to claim 1, wherein the first light-emitting element portion has a reflector on the mounting substrate side of the light-emitting portion including the photonic crystal layer and the active layer, and the saturable absorption region is provided in at least the reflector.

Images