CN118382972A

CN118382972A - Control device, control method, semiconductor laser device, distance measuring device, and in-vehicle device

Info

Publication number: CN118382972A
Application number: CN202280081726.5A
Authority: CN
Inventors: 前田修; 木村基
Original assignee: Sony Semiconductor Solutions Corp
Current assignee: Sony Semiconductor Solutions Corp
Priority date: 2021-12-14
Filing date: 2022-11-30
Publication date: 2024-07-23
Also published as: JPWO2023112675A1; WO2023112675A1; DE112022005966T5

Abstract

To rapidly switch the polarization direction of light emitted from, for example, a semiconductor laser device. [ solution ] the control device comprises: a first control circuit connected to the light emitting unit and having a control circuit for controlling a current flowing through the light emitting unit, the control circuit controlling the current flowing through the light emitting unit such that a polarization direction of light emitted from the light emitting unit becomes a first polarization direction; and a second control circuit controlling a current flowing through the light emitting unit such that a polarization direction of light emitted from the light emitting unit is switched from a first polarization direction to a second polarization direction different from the first polarization direction.

Description

Control device, control method, semiconductor laser device, distance measuring device, and in-vehicle device

Technical Field

The present technology relates to a control device, a control method, a semiconductor laser device, a distance measuring device, and an in-vehicle device.

Background

Vertical Cavity Surface Emitting Lasers (VCSELs) using GaAs, inP, or the like as a substrate have been proposed as one of light sources for distance measuring devices and the like. For example, the following patent document 1 discloses a surface emitting semiconductor laser having a configuration capable of stabilizing light output in a polarization direction.

List of references

Patent literature

Patent document 1: japanese patent application laid-open No. 2008-16844.

Disclosure of Invention

Problems to be solved by the invention

In this field, it is desirable to perform control suitable for the field of application of the semiconductor laser device. For example, in the case of applying the semiconductor laser device to the distance measuring device, it is desirable to perform control for improving the distance measuring accuracy.

The object of the present technology is, for example, to provide a control device, a control method, a semiconductor laser device, a distance measuring device, and an in-vehicle device that perform control to improve the distance measurement accuracy.

Solution to the problem

The present technology is, for example, a control device including:

A control circuit connected to the light emitting unit and controlling a current flowing into the light emitting unit, wherein,

The control circuit includes:

a first control circuit controlling a current flowing into the light emitting unit such that a polarization direction of light emitted from the light emitting unit is a first polarization direction; and

And a second control circuit controlling a current flowing into the light emitting unit to switch a polarization direction of light emitted from the light emitting unit from a first polarization direction to a second polarization direction different from the first polarization direction.

The present technology is, for example, a semiconductor laser device including:

A light emitting unit;

A control circuit connected to the light emitting unit and controlling a current flowing into the light emitting unit; and

A polarizer in which

The control circuit includes:

A second control circuit controlling a current flowing into the light emitting unit to switch a polarization direction of light emitted from the light emitting unit from a first polarization direction to a second polarization direction different from the first polarization direction, and

The polarizer blocks light of a first polarization direction and transmits light of a second polarization direction.

The present technology may be a distance measuring device including the above-described semiconductor laser device or a vehicle-mounted device including the distance measuring device.

Drawings

Fig. 1 is a diagram showing references when problems to be considered in the present technology.

Fig. 2 is a diagram showing references when problems to be considered in the present technology.

Fig. 3 is a diagram showing references when problems to be considered in the present technology.

Fig. 4 is a diagram showing an example of a schematic configuration of the semiconductor laser device according to the first embodiment.

Fig. 5 is a graph showing X-polarized light and Y-polarized light.

Fig. 6 is a diagram showing an example configuration of a control device or the like according to the first embodiment.

Fig. 7 is a diagram showing an example configuration of a control device or the like according to the first embodiment.

Fig. 8 is a graph showing the response of the VCSEL to control performed according to the first embodiment.

Fig. 9 is a block diagram showing an example configuration of a distance measuring device according to the first embodiment.

Fig. 10 is a graph showing an example of the timing of the preliminary light emission and the timing of the main light emission.

Fig. 11 is a diagram showing a light emitting unit included in a VCSEL according to the second embodiment.

Fig. 12 is a diagram showing a light emitting unit included in a VCSEL according to the second embodiment.

Fig. 13 is a diagram showing a light emitting unit included in a VCSEL according to the second embodiment.

Fig. 14 is a diagram showing a light emitting unit included in a VCSEL according to the second embodiment.

Fig. 15 is a diagram showing a light emitting unit included in a VCSEL according to the second embodiment.

Fig. 16 is a diagram showing a light emitting unit included in a VCSEL according to the second embodiment.

Fig. 17 is a diagram showing a light emitting unit included in a VCSEL according to the third embodiment.

Fig. 18 is a block diagram showing an example of a schematic configuration of the vehicle control system.

Fig. 19 is an explanatory diagram showing an example of mounting positions of the outside-vehicle information detecting section and the imaging section.

Detailed Description

Embodiments of the present technology and the like are described below with reference to the drawings. Note that description will be made in the following order.

< Problems to be considered in the art >

< First embodiment >

< Second embodiment >

< Third embodiment >

< Modification >

< Example application >

Note that the embodiments and the like described below are preferable specific examples of the present technology, and the content of the present technology is not limited to these embodiments and the like.

< Problems to be considered in the art >

First, in order to facilitate understanding of the present technology, problems to be considered in the present technology are described with reference to fig. 1 to 3. Note that in the following, distance measurement, or specifically, VCSEL used in a direct time of flight (dtorf) system is described as an example.

Fig. 1 is a diagram showing an example of a system configuration of a dtofs system. The laser driver 2, the VCSEL 3, and the light receiving element 4 are mounted on a Printed Circuit Board (PCB) 1, and connected by a copper foil pattern (not shown). As the light receiving element 4, for example, a Single Photon Avalanche Diode (SPAD) is used. The distance measurement target 5 is irradiated with light emitted from the VCSEL 3, and reflected light from the distance measurement target 5 is received by the light receiving element 4. The time of flight of light (the reciprocation time of light) is multiplied by the speed of light, and the result is divided by 2 to calculate the distance to the measurement target 5.

Meanwhile, in order to increase the distance measurement distance and the distance measurement accuracy, the VCSEL needs to have the capability of outputting as many photons as possible in a short time. However, as the input current becomes larger, both the rise time and the fall time of the current waveform output by the laser driver 2 become longer. Since the light output from the VCSEL 3 also follows the operation of the laser driver 2, the pulsed light emission applied to the distance measurement target 5 has a broad photon distribution with respect to the time axis (see fig. 2A). Thus, a change in response from the light receiving element 4 (SPAD in this example) occurs (see fig. 2B). The detection timing varies due to a variation between responses from the light receiving elements 4, and the ToF accuracy decreases due to a difference in detection timing (see fig. 2C). Note that circles in fig. 2A and 2B schematically indicate photons.

Fig. 3A is a diagram schematically showing the current injected by the laser driver 2. In fig. 3A, the horizontal axis represents time (nanoseconds), the vertical axis represents the magnitude of current (mA), ON (ON) represents timing at which current starts to be injected into the VCSEL 3, and OFF (OFF) represents timing at which current stops to be injected into the VCSEL 3. Meanwhile, in fig. 3B, the horizontal axis represents time (nanoseconds), and the vertical axis represents the light output (mW) of the VCSEL 3. Line L1 in fig. 3B represents a time waveform of the light output of the VCSEL 3, and line L2 represents accumulated energy obtained by time-integrating the light output.

As shown in fig. 3A, the VCSEL 3 oscillates for several hundred picoseconds (ps) after the on timing, and thus, a variation in oscillation delay between transmitters becomes a factor of deterioration in the distance measurement accuracy. For example, the accuracy of a three-dimensional image obtained by distance measurement of multi-point irradiation deteriorates. Further, even if the current injection is turned off, the accumulated energy does not converge and gradually increases. In this way, the universal system increases the problem of eye-safety compliance. In view of the above, the present technology is described in detail below with reference to embodiments.

< First embodiment >

[ Example configuration of semiconductor laser device ]

Fig. 4 shows an example of a schematic configuration of a semiconductor laser device (semiconductor laser device 10) according to the first embodiment. For example, the semiconductor laser device 10 includes a VCSEL 20, a control device 30 that controls the operation of the VCSEL 20, and a polarizer 40 disposed in an optical path LM of light emitted from the VCSEL 20.

As the VCSEL 20, a known VCSEL 20 may be employed. For example, VCSELs having surface emitting lasers (light emitting units described later) disposed in an array on a semiconductor substrate may be employed as the VCSELs 20. When control (described in detail later) is performed by the control device 30, the VCSEL 20 emits light whose polarization direction is the Y direction (an example of the first polarization direction), which will be hereinafter appropriately referred to as Y polarized light, or light whose polarization direction is the X direction (an example of the second polarization direction) orthogonal to the Y direction, which will be hereinafter appropriately referred to as X polarized light. As shown in fig. 5, Y polarized light is output from the surface emitting laser until the injection current of the surface emitting laser with respect to the VCSEL 20 reaches a threshold Th, and when the injection current becomes greater than the threshold Th, X polarized light is output from the surface emitting laser. The threshold Th is basically a determined current value. Polarizer 40 is a polarizer that blocks Y polarized light and transmits X polarized light.

Fig. 6 is a diagram for explaining a configuration example of the control device 30 according to the present embodiment. Note that fig. 6 shows a light emitting unit (light emitting unit 211) included in the VCSEL 20. In the present embodiment, the control device 30 is connected to the plurality of light emitting units 211. Note that, in theory, the light emitting unit 211 may be one light emitting unit. Further, even in the case of a configuration including a plurality of light emitting units 211 as in the present embodiment, the light emitting units 211 are collectively referred to as light emitting units 211 as appropriate.

The control device 30 includes, for example, a first control circuit 31 and a second control circuit 32. The first control circuit 31 controls the current flowing into the light emitting unit 211 such that the polarization direction of the light emitted from the light emitting unit 211 becomes Y-polarized light. The second control circuit 32 controls the current flowing into the light emitting unit 211 such that the polarization direction of the light emitted from the light emitting unit 211 is switched from Y-polarized light to X-polarized light having a polarization direction different from that of the Y-polarized light.

The first control circuit 31 includes, for example, a switching element 311, a switching element 312, a first driving circuit 313, a first current source 314, a switching element 315, and a resistor 316. The second control circuit 32 includes, for example, a switching element 321, a switching element 322, a second driving circuit 323, a second current source 324, a switching element 325, and a resistor 326. In this embodiment mode, an N-channel Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is used as the switching element 311, the switching element 312, the switching element 315, the switching element 321, the switching element 322, and the switching element 325. Of course, P-channel MOSFETs or other switching elements may be used as these switching elements. The switching element 312 as an example of the first switching element turns on/off the operation of the switching element 311. Further, a switching element 322 as an example of the second switching element turns on/off the operation of the switching element 321.

The drain of the switching element 311 included in the first control circuit 31 is connected to an electrode of the light emitting unit 211, or specifically, to a cathode electrode (in the case of the present embodiment, a common cathode electrode in a plurality of light emitting units 211). The source of the switching element 311 is connected to the drain of the switching element 312, and the source of the switching element 312 is grounded. The first driving circuit 313 is connected to the gate of the switching element 312. The first driving circuit 313 controls on/off of the switching element 312. For example, when the first driving circuit 313 inputs a logic high level signal to the gate of the switching element 312, the switching element 312 is turned on.

The gate and drain of the switching element 315 are connected to the first current source 314, and the source of the switching element 315 is grounded via the resistor 316. The gate and drain voltages of the switching element 315 generated in this circuit are supplied to the gate of the switching element 311. The gate voltage of the switching element 311 determines the first drive current at which the switching element 311 drives the VCSEL 20. The magnitude of which may vary with the current value of current source 314.

In the case where the VCSEL 20 is not driven, the first driving circuit 313 inputs a logic low level signal to the gate of the switching element 312 to turn off the switching element 312. At the same time, the switching element 311 is turned off. Therefore, the first driving current does not flow into the VCSEL 20, and the VCSEL 20 does not emit light. When the first driving circuit 313 inputs a logic high level signal to the gate of the switching element 312, the switching element 312 is turned on. At the same time, the switching element 311 is turned on, so that a first driving current flows into the VCSEL 20 to cause the VCSEL 20 to emit light. As described above, the first driving current may vary with the current value of the current source 314, and be set to a current having a magnitude up to the above-described threshold Th. Accordingly, the polarization direction of light emitted from the VCSEL 20 is switched to the Y direction by the first driving current.

The drain of the switching element 321 included in the second control circuit 32 is connected to the cathode electrode of the light emitting unit 211 (in the case of the present embodiment, a common cathode electrode in a plurality of light emitting units 211). A source of the switching element 321 is connected to a drain of the switching element 322, and a source of the switching element 322 is grounded. The second driving circuit 323 is connected to the gate of the switching element 322. The second driving circuit 323 controls on/off of the switching element 322. For example, when the second driving circuit 323 inputs a logic high level signal to the gate of the switching element 322, the switching element 322 is turned on.

The gate and drain of the switching element 325 are connected to the second current source 324, and the source of the switching element 325 is grounded via a resistor 326. The gate voltage and the drain voltage of the switching element 325 generated in this circuit are supplied to the gate of the switching element 321. The gate voltage of the switching element 321 determines the second drive current at which the switching element 321 drives the VCSEL 20. The magnitude of which may vary with the current value of current source 324.

In the case where the VCSEL 20 is not driven, the second driving circuit 323 inputs a logic low level signal to the gate of the switching element 322 to turn off the switching element 322. At the same time, the switching element 321 is turned off. Therefore, the second driving current does not flow into the VCSEL 20, and the VCSEL 20 does not emit light. When the second driving circuit 323 inputs a logic high level signal to the gate of the switching element 322, the switching element 322 is turned on. At the same time, the switching element 321 is turned on, so that a second driving current flows into the VCSEL 20 to cause the VCSEL 20 to emit light. The second driving current is a current added to the first driving current so that the current flowing into the VCSEL 20 is greater than the above-described threshold Th. Accordingly, the polarization direction of light emitted from the VCSEL 20 is switched to the X direction by the first driving current and the second driving current.

[ Example operation of control Circuit ]

Next, an example operation of the control device 30 is described with reference to timing charts shown in fig. 7A to 7D. First, as shown in fig. 7A, when the switching element 312 is turned on at a predetermined timing t1 by the first driving circuit 313, a first driving current flows into the VCSEL 20, and the VCSEL 20 emits light. As described above, the light emitted from the VCSEL 20 herein is Y polarized light. The state of emitting Y polarized light from the VCSEL 20 is also referred to as ready-to-emit (PRELIMINARY EMISSION).

As shown in fig. 7B, at a predetermined timing t2 later in time than the timing t1, when the switching element 312 is turned on, the switching element 322 is turned on by the second driving circuit 323. Thus, in addition to the first drive current, a second drive current flows into the VCSEL 20. That is, when a driving current exceeding the threshold Th flows, the light emitted from the VCSEL 20 is switched from Y-polarized light to X-polarized light. The state of emitting X-polarized light from the VCSEL 20 is also referred to as the primary emission (PRINCIPAL EMISSION).

In the preliminary emission state, Y-polarized light emitted from the VCSEL 20 may be applied to a target (a specific example of which is a distance measurement target) (see fig. 7C). However, in the present embodiment, the polarizer 40 is disposed in the optical path of the VCSEL 20, and thus, the light output to the target is limited to X-polarized light (see fig. 7D).

Fig. 8A to 8C are graphs for explaining the response of the VCSEL to the above control. Fig. 8A is a graph schematically showing light during preliminary emission and light during main emission on the horizontal axis as a time axis. The polarization direction from the preliminary emission to the main emission is switched from the Y direction to the X direction only in about a few ps. Thus, a very sharp optical waveform as shown in fig. 8B is obtained. Since the timing of the light rise follows the time at which the switching element 322 is turned on, the influence of the oscillation delay is also minimized. Further, as shown in fig. 8C, the light output to the target immediately becomes 0 at the timing when the switching element 322 is turned off, and thus, the accumulated energy of the light output does not gradually increase. As described above, highly accurate distance measurements can be performed in a dtif system while reducing problems in eye-safety compliance.

< Example configuration of distance measurement device >

Next, an example configuration of the distance measuring device 50 in the case where the above-described semiconductor laser device 10 is applied to the distance measuring device (distance measuring device 50) is described with reference to fig. 9. The distance measuring device 50 is a device that measures a distance to the distance measurement target 60.

The distance measuring device 50 includes a timing signal generating unit 501, a light receiving unit 502, an amplifying unit 503, a waveform shaping unit 504, and a time difference measuring unit 505 in addition to the configuration (VCSEL 20, control device 30, and polarizer 40) according to the semiconductor laser device 10.

The timing signal generation unit 501 generates a timing signal, and supplies the generated timing signal to the control device 30. Specifically, the timing signal generation unit 501 generates a preliminary transmission timing signal TSA for causing the VCSEL 20 to perform preliminary transmission and a main transmission timing signal TSB for causing the VCSEL 20 to perform main transmission. As shown in fig. 10, the main transmission timing signal TSB is generated by a predetermined time difference TD after the timing of generating the preliminary transmission timing signal TSA. The preliminary light emission timing signal TSA and the main light emission timing signal TSB are supplied to the control device 30. Further, the main transmission timing signal TSB is supplied to the time difference measurement unit 505.

The control device 30 turns on the switching element 312 when the preliminary transmission timing signal TSA is input. Further, the switching element 311 is turned on. Accordingly, the first driving current flows into the VCSEL 20, and thus, Y polarized light is emitted from the VCSEL 20. However, the emitted Y polarized light is blocked by the polarizer 40, and therefore, the distance measurement target 60 is not irradiated with the Y polarized light.

Further, control device 30 turns on switching element 322 at the timing when main emission timing signal TSB is input. In addition, the switching element 321 is turned on. Accordingly, the first drive current and the second drive current flow into the VCSEL 20, and thus, X-polarized light is emitted from the VCSEL 20. Since the polarizer 40 transmits X-polarized light, the distance measurement object 60 is irradiated with the X-polarized light.

The light receiving unit 502 receives reflected light from the distance measurement object 60. In this embodiment, a multi-pixel SPAD is employed as the light receiving unit 502. As the light receiving unit 502, a photodiode or an avalanche photodiode may be employed. The light reception signal is output from the light reception unit 502 that receives the reflected light.

The amplifying unit 503 amplifies the voltage of the light-receiving signal supplied from the light-receiving unit 502. For example, the amplifying unit 503 linearly amplifies the voltage of the light-receiving signal with a predetermined amplification factor. As the amplifying unit 503, a limiting amplifier or the like can be used.

The waveform shaping unit 504 shapes the waveform of the optical reception signal amplified by the amplifying unit 503. Then, the waveform shaping unit 504 measures the light reception timing at which the light reception unit 502 receives the reflected light by detecting an edge point at which the voltage of the light reception signal reaches a predetermined threshold value, and outputs a light reception timing signal TSC indicating the measured light reception timing.

The time difference measurement unit 505 calculates the distance to the distance measurement target 60 in one frame period based on the main transmission timing signal TSB and the light reception timing signal TSC. For example, the time difference measurement unit 505 obtains the difference between the main emission timing signal TSB and the light reception timing signal TSC to calculate the time of flight of the X-polarized light emitted from the VCSEL 20, multiplies the time of flight by the speed of light c, and multiplies the result by 1/2 to calculate the distance to the distance measurement target 60. Note that, in the process of calculating the distance, some other process such as a correction process may be performed. The distance calculated by the time difference measuring unit 505 is used according to a vehicle safety system or an application for three-dimensional measurement of an object, or the like.

< Second embodiment >

Next, a second embodiment is described. Note that in the description of the second embodiment, the same or similar components as those of the above-described embodiment are denoted by the same reference numerals as those used in the above-described embodiment, and the description thereof is appropriately omitted herein. Further, the contents described in the first embodiment can also be applied to the second embodiment unless otherwise specified. The specific configuration of the VCSEL is one of the features of the second embodiment.

Fig. 11 is a top view of a light emitting unit included in a VCSEL (VCSEL 20A) according to the second embodiment. Fig. 12 shows a cross-sectional configuration taken along the line A-A defined in fig. 11. Fig. 13 shows a cross-sectional configuration taken along line B-B defined in fig. 11.

The VCSEL 20A includes a light emitting unit 200 on one surface side of the substrate 100. The light emitting unit 200 is formed by sequentially stacking a lower DBR mirror layer 11 (first multilayer reflector), a lower spacer layer 14, an active layer 15, an upper spacer layer 16, a current confinement layer 17, an upper DBR mirror layer 18 (second multilayer reflector), and a contact layer 19 from the substrate 100 side. In a part of the lower DBR mirror layer 11, the lower spacer layer 14, the active layer 15, the upper spacer layer 16, the current confinement layer 17, the upper DBR mirror layer 18, and the contact layer 19 of the light emitting unit 200, a cylindrical mesa portion 21 having a width of about 10 μm to 30 μm, for example, and a groove portion 22 surrounding the mesa portion 21 are formed.

The groove portion 22 is an annular groove having a non-uniform width and has a non-uniform depth depending on (or proportional to) the width of the groove. Specifically, at a portion corresponding to one axis (line A-A in fig. 11) parallel to the lamination surface and extending through the center portion of the table face portion 21, a pair of grooves 22A having a width Ly in the radial direction and a width Lx in the circumferential direction are provided, and a pair of grooves 22B communicating with these grooves 22A and having a width Δr in the radial direction are provided. The depth D1 of the groove 22A reaches a lower first DBR mirror layer 12 (described later) of the lower DBR mirror layer 11. On the other hand, the depth D2 of the groove 22B does not reach the lower first DBR mirror layer 12. That is, the depth D2 of the groove 22B is shallower than the depth D1 of the groove 22A. Therefore, the height of the mesa portion 21 is uneven in conformity with the depth of the recess portion 22, and the layer configuration exposed from the side of the mesa portion 21 varies depending on the depth of the recess portion 22. Note that fig. 13 shows a case where the groove 22B reaches a lower second DBR mirror layer 13 (described later) of the lower DBR mirror layer 11.

Here, lx and Ly are preferably not reduced in size of an etching rate described later, and are preferably 5 μm or more. In addition, Δr is smaller than Lx and Ly, preferably a size in which the etching rate of the groove 22B is lower than that of the groove 22A due to a loading effect described later, and is preferably 1 μm or more and 3 μm or less, or more preferably 2 μm.

The substrate 100 is, for example, an n-type GaAs substrate. The GaAs substrate is preferably a (100) plane substrate, for example, but may be a special substrate such as a (n 11) plane substrate (n is an integer).

The lower DBR mirror layer 11 has a structure in which a lower first DBR mirror layer 12 (third multilayer reflector) and a lower second DBR mirror layer 13 (fourth multilayer reflector) are laminated in this order from the substrate 100 side. The lower first DBR mirror layer 12 is formed by laminating a plurality of sets of low refractive index layers 12A and high refractive index layers 12B. The low refractive index layer 12A is formed of, for example, n-type Al _x1Ga_1-x1 As having an optical thickness λ/4 (λ is an oscillation wavelength), and the high refractive index layer 12B is formed of, for example, n-type Al _x2Ga_1-x2 As having an optical thickness λ/4. The lower second DBR mirror layer 13 is formed by laminating a plurality of sets of low refractive index layers 13A and high refractive index layers 13B. The low refractive index layer 13A is formed of, for example, n-type Al _x3Ga_1-x3 As having an optical thickness of λ/4, and the high refractive index layer 13B is formed of, for example, n-type Al _x4Ga_1-x4 As having an optical thickness of λ/4. Note that examples of the n-type impurity include, for example, silicon (Si) and selenium (Se).

Here, al composition values x1 to x4 in the lower DBR mirror layer 11 satisfy expression (1) shown below. Therefore, the low refractive index layer 12A of the lower first DBR mirror layer 12 is more easily oxidized than the low refractive index layer 13A of the lower second DBR mirror layer 13, and the characteristic oxidation is less easily oxidized than the current confinement layer 17 or as easily oxidized as the current confinement layer 17.

1≥x9≥x1>(x3，x10)>0.8>(x2，x4)≥0 (1)

In expression (1), (x 3, x 10) represents x3 or x10, and (x 2, x 4) represents x2 or x4. Further, x9 is a value of an Al composition contained in a material forming the current confinement layer 17, and x10 is a value of an Al composition contained in a material forming the low refractive index layer of the upper DBR mirror layer 18. Further, 0.8 corresponds to a boundary between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer.

However, in each low refractive index layer 12A of the lower first DBR mirror layer 12, the oxidized portion 300 is formed by oxidizing a portion of the low refractive index layer 12A in a region (side portion of the mesa portion 21) surrounding the groove 22A at the periphery of a region corresponding to the central region of the mesa portion 21 (light emitting region 15A described later). The oxidized part 300 includes a pair of oxidized layers 31A and 32A, and the pair of oxidized layers 31A and 32A are arranged to oppose each other with a distance Dox1, with a region of the lower first DBR mirror layer 12 corresponding to the light emitting region 15A interposed therebetween (which region is also a region corresponding to a current injection region 17B described later), and is formed in conjunction with a groove 22A having a larger depth in the groove part 22. That is, the oxidized portions 300 are unevenly distributed in the rotation direction around the light emitting region 15A, and uneven stress corresponding to the distribution is generated in the active layer 15.

Here, when the radial length of the current injection region 17B is set to Dox2, the distance Dox1 is preferably longer than Dox2, and in the case where it is desired to reduce the higher-order lateral mode oscillation, it is preferably not shorter than dox2+1 μm and not longer than 15 μm. Further, in the case where it is desired to further reduce the higher-order transverse mode oscillation, the distance Dox1 is preferably not shorter than dox2+1 μm and not longer than 10 μm. Further, in the case where it is desired to reduce the loss of light emission efficiency due to the oxide layers 31A and 32A, the distance Dox1 is preferably longer than Dox2, and more preferably 1.1×dox2 or more.

The oxide layers 31A and 32A contain alumina (Al ₂O₃), and are obtained by oxidizing high-concentration Al contained in the low refractive index layer 12A from the side surface sides of the mesa portion 21 and the groove portion 22 as described later. Thus, each oxide layer 31A forms a multilayer film 310 (first multilayer film) that is laminated and disposed in the lower DBR mirror layer 11 with the high refractive index layer 12B interposed therebetween, and each oxide layer 32A forms a multilayer film 320 (second multilayer film) that is laminated and disposed in the lower DBR mirror layer 11 with the high refractive index layer 12B interposed therebetween. Note that the lower first DBR mirror layer 12 is not exposed through the portion of the side surface of the mesa portion 21 facing the groove 22B, and the oxide layers 31A and 32A are not distributed in portions other than the portion adjacent to the groove 22A.

The lower spacer layer 14 is formed of, for example, al _x8Ga_1-x8 As (0 < x8 < 1). For example, the active layer 15 is formed of GaAs-based material. In the active layer 15, a region facing a current injection region 17B described later is a light emitting region 15A, a central region (light emitting central region) of the light emitting region 15A is a region where fundamental transverse mode oscillation mainly occurs, and an outer edge region of the light emitting region 15A surrounding the light emitting central region is a region where higher-order transverse mode oscillation mainly occurs. Y polarized light is generated by the fundamental transverse mode oscillation and X polarized light is generated by the higher order transverse mode oscillation. The upper spacer layer 16 is formed of, for example, al _x12Ga_1-x12 As (0 < X12 < 1). It is desirable that the lower spacer layer 14, the active layer 15, and the upper spacer layer 16 contain no impurity, but may contain p-type or n-type impurities. Examples of p-type impurities include zinc (Zn), magnesium (Mg), and beryllium (Be).

The current confinement layer 17 has a current confinement region 17A in its outer edge region and a current injection region 17B in its central region. The current injection region 17B is formed of, for example, p-type Al _x9Ga_1-x9 As (0 < x 9. Ltoreq.1). The current confinement region 17A contains alumina (Al ₂O₃), and is obtained by oxidizing high-concentration Al contained in the Al _x9Ga_1-x9 As layer 17D from the side surface side of the mesa portion 21 As described later. That is, the current confinement layer 17 has a function of confining the current.

The current confinement region 17A has a quadrangular shape (e.g., diamond shape) having diagonal lines in the [011] direction and the [01-1] direction, and has in-plane anisotropy. The reason why the current confinement region 17A is a quadrangle having diagonal lines in the [011] direction and the [01-1] direction As described above is that the oxidation rate of Al _x9Ga_1-x9 As in the [011] direction and the [01-1] direction is different from the oxidation rates in the [001] direction and the [010] direction forming an angle of 45 ° with these directions. Here, the length Dox2 of the diagonal line of the current confinement region 17A is preferably not shorter than 3 μm and not longer than 8 μm in the case where it is desired to reduce the higher-order lateral mode oscillation. Further, in the case where it is desired to further reduce the higher-order transverse mode oscillation, the length Dox2 is preferably not shorter than 3 μm and not longer than 5 μm.

The upper DBR mirror layer 18 is formed by stacking a plurality of sets of low refractive index layers and high refractive index layers. The low refractive index layer is formed of, for example, p-type Al _x10Ga_1-x10 As (0 < x10 < 1) having an optical thickness of λ/4, and the high refractive index layer is formed of, for example, p-type Al _x11Ga_1-x11 As (0 < x11 < 1) having an optical thickness of λ/4. The contact layer 19 is formed of, for example, p-type GaAs.

In addition, in the VCSEL 20A of the present embodiment, the protective film 23 is formed on the outer edge portion of the upper surface of the mesa portion 21, the inner surface of the groove portion 22, and the surface of the contact layer 19 other than the mesa portion 21. On the surface of the contact layer 19, an annular upper electrode 24 having a light outlet 24A is formed in a region corresponding to the above-described current injection region 17B, and an upper electrode pad 25 is formed on the surface of a portion of the protective film 23 remote from the mesa portion 21. Further, as shown in fig. 11, a connection portion 26 is formed on the surface of the portion of the protective film 23 including the groove portion 20B, and the upper electrode 24 and the upper electrode pad 25 are electrically connected to each other through the connection portion 26. Also, a lower electrode 27 is formed on the rear surface of the substrate 100.

The protective film 23 is formed of, for example, an insulating material such as oxide or nitride, and is formed so as to cover the inner surface of the groove portion 22 and the vicinity thereof from the peripheral portion of the contact layer 19. The upper electrode 24 and the upper electrode pad 25 are formed by sequentially stacking, for example, a titanium (Ti) layer, a platinum (Pt) layer, and a gold (Au) layer, and are electrically connected to the contact layer 19. The connection portion 26 is formed by, for example, forming a plating layer on a laminated structure formed by laminating a Ti layer, a Pt layer, and an Au layer in this order. The lower electrode 27 has, for example, a structure in which an alloy layer of gold (Au) and germanium (Ge), a nickel (Ni) layer, and a gold (Au) layer are sequentially stacked from the side of the substrate 100, and is electrically connected to the substrate 100.

Although based on the above-described configuration, the VCSEL according to the present embodiment has the configuration of the VCSEL 20B described below. Fig. 14 shows a top surface configuration of the VCSEL 20B according to the present example. Fig. 15 is an enlarged view of the vicinity of the light outlet 24A in a cross-sectional configuration taken along the line A-A defined in fig. 14. Fig. 16 is an enlarged view of the vicinity of the light outlet 24A in a cross-sectional configuration taken along the line B-B defined in fig. 14. The VCSEL 20B is different from the configuration shown in fig. 11 and the like in that a lateral mode adjusting layer 70 as an example of a lateral mode adjusting section is provided together with the light outlet 24A.

The lateral mode adjustment layer 70 includes a first adjustment layer 71, a second adjustment layer 72, and a third adjustment layer 73, and the first adjustment layer 71 and the second adjustment layer 72 are sequentially laminated in a central region of the light outlet 24A, which is a region where the fundamental lateral mode oscillation mainly occurs. The third adjustment layer 73 is formed in an outer edge region around the center region, which is a region where the higher-order transverse mode oscillation mainly occurs.

Note that in fig. 14 to 16, in order to further reduce the higher-order transverse mode oscillation in the direction in which the grooves 22B face each other, the first adjustment layer 71 and the second adjustment layer 72 have, for example, rectangular shapes in which the width in the direction in which the grooves 22B face each other is smaller than the width in the direction in which the grooves 22A face each other, but may have some other shapes such as a circle.

The first adjustment layer 71 is formed of a substance having a thickness (2 a-1) λ/4n ₁ (a is an integer of 1 or more, n ₁ is a refractive index) and a refractive index n ₁ lower than that of the high refractive index layer provided on the surface of the upper DBR mirror layer 18. For example, the material is a dielectric material such as silicon oxide (SiO ₂). The width of the first regulation layer 71 in the direction in which the grooves 22B face each other is substantially equal to the width of the region where the fundamental transverse mode vibration mainly occurs, and is preferably not less than 3.0 μm and not more than 5.0 μm.

The second adjustment layer 72 is formed of a material having a thickness (2 b-1) λ/4n ₂ (b is an integer of 1 or more, n ₂ is a refractive index) and a refractive index n ₂ higher than a refractive index n ₂ of the first adjustment layer 71. Such as a dielectric material, such as silicon nitride (SiN).

The third adjustment layer 73 is formed of a material having a thickness (2 c-1) λ/4n ₃ (c is an integer of 1 or more, n ₃ is a refractive index) and a refractive index n ₃ lower than that of the first adjustment layer 71. Such as a dielectric material, such as silicon nitride (SiN). Note that the second adjustment layer 72 and the third adjustment layer 73 are preferably formed with the same thickness and the same material. Thus, these layers can be formed together, and the manufacturing process can be simplified.

Here, in the case where the reflectance of the central region of the light outlet 24A is represented by R1, the reflectance of the outer edge region around the central region is represented by R2, and the reflectance in the case where these adjustment layers are not provided within the light outlet 24A is represented by R3, the respective refractive indices are preferably adjusted so as to satisfy the relationship shown in the following expression (2).

R1≥R3>R2 (2)

In the configuration according to the present example, the first adjustment layer 71 is provided on the upper DBR mirror layer 18A formed of a semiconductor material. Therefore, it is very easy to selectively perform etching on the first adjustment layer 71, and it is not necessary to form the first adjustment layer 71, the second adjustment layer 72, and the third adjustment layer 73 into complicated shapes. Thus, the VCSEL 20B can be easily manufactured.

The control of the control device 30 described in the first embodiment is performed on the VCSEL 20B having the above-described configuration. Thereby, only the X-polarized light is emitted to the distance measurement object 60.

< Third embodiment >

Next, a third embodiment is described. Note that in the description of the third embodiment, the same or similar components as those in the above description are denoted by the same reference numerals as those used in the above embodiment, and the description thereof is omitted herein as appropriate. Further, the contents described in the first embodiment and the second embodiment can also be applied to the third embodiment unless otherwise specified. The third embodiment is different from the VCSEL according to the second embodiment in a part of the configuration of the VCSEL.

Fig. 17A is a top view of a light emitting unit included in a VCSEL according to a third embodiment. Fig. 17B shows a cross-sectional configuration taken along the line A-A defined in fig. 17A. The basic configuration is the same as that shown in fig. 16, but the first adjustment layer 71, the second adjustment layer 72, and the third adjustment layer 73 according to the present embodiment have a graded structure engraved with linear grooves.

In the first adjustment layer 71 and the second adjustment layer 72 at the emission center portion as the fundamental transverse mode oscillation region, linear grooves are engraved in the Y direction (an example of the first direction). On the other hand, a linear groove in the X direction (an example of the second direction) is engraved in the third regulation layer 73 as the peripheral region. In this configuration, the light whose polarization direction is the Y direction of the emission center portion has high reflection characteristics, and the light whose polarization direction is the X direction of the peripheral region has high reflectivity. The current before oscillation in the fundamental mode is switched to Y polarized light, and beyond this, the current is switched to X polarized light. By incorporating such a light source into the VCSEL according to the first embodiment, it becomes possible to limit a large number of photons in a short time, and thus, high-speed and high-precision distance measurement becomes possible. Note that, in the case of the configuration according to the present embodiment, no oxidized portion is formed on the side portion of the mesa portion 21.

< Modification >

Although the embodiments of the present technology have been specifically described, the content of the present technology is not limited to the above-described embodiments, and various modifications may be made based on the technical idea of the present technology. Note that the same or similar components as those of the above-described embodiment are denoted by the same reference numerals as those described above, and description thereof is omitted herein as appropriate.

The switching element 312 may be constantly in an on state during the operation of the above-described semiconductor laser device 10. However, from the viewpoint of lower power consumption, it is preferable that each distance measuring unit (one frame) turns off the switching element 312. Moreover, the semiconductor laser device 10 according to the present technology can be applied to electronic devices other than distance measuring devices.

Note that the effects described in this specification are merely examples and not restrictive, and other effects may also be achieved.

< Example application >

Furthermore, the techniques according to the present technology may be applied to various products, not limited to the above-described example applications. For example, the technology according to the present technology may also be implemented as a device mounted on any type of movable structure, such as an automobile, an electric automobile, a hybrid electric automobile, a motorcycle, a bicycle, a personal moving body, an airplane, an unmanned aerial vehicle, a ship, a robot, a construction machine, an agricultural machine (tractor).

Fig. 18 is a block diagram showing an example of a schematic configuration of a vehicle control system 7000 as an example of a moving structure control system to which the technology according to the present technology can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected to each other via a communication network 7010. In the example shown in fig. 18, the vehicle control system 7000 includes a drive system control unit 7100, a vehicle body system control unit 7200, a battery control unit 7300, an outside-vehicle information detection unit 7400, an inside-vehicle information detection unit 7500, and an integrated control unit 7600. For example, the communication network 7010 that connects a plurality of control units to each other may be an in-vehicle communication network conforming to a standard such as a Controller Area Network (CAN), a local area network (LIN), a Local Area Network (LAN), or FlexRay (registered trademark).

Each control unit includes: a microcomputer that performs arithmetic processing according to various programs; a storage section that stores a program executed by a microcomputer, parameters for various operations, and the like; and a driving circuit that drives the various control target devices. Each control unit further comprises: a network interface (I/F) for performing communication with other control units via a communication network 7010; and a communication I/F for communicating with devices, sensors, etc. inside and outside the vehicle by cable communication or wireless communication. In fig. 18, a microcomputer 7610, a general-purpose communication I/F7620, a special-purpose communication I/F7630, a positioning portion 7640, a beacon receiving portion 7650, an in-vehicle device I/F7660, an audio/image output portion 7670, an in-vehicle network I/F7680, and a storage portion 7690 are shown as functional configurations of an integrated control unit 7600. Similarly, the other control units each include a microcomputer, a communication I/F, a storage section, and the like.

The drive system control unit 7100 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 7100 functions as a control device of a drive force generating device (such as an internal combustion engine, a drive motor, or the like) for generating a drive force of the vehicle, a drive force transmitting mechanism for transmitting the drive force to wheels, a steering mechanism for adjusting a steering angle of the vehicle, a braking device for generating a braking force of the vehicle, or the like. The drive system control unit 7100 may have a function as a control device of an Antilock Brake System (ABS), an Electronic Stability Control (ESC), or the like.

The vehicle state detection portion 7110 is connected to the drive system control unit 7100. The vehicle state detection unit 7110 includes, for example, at least one of a gyro sensor that detects an angular velocity of an axial rotational motion of a vehicle body, an acceleration sensor that detects an acceleration of the vehicle, and a sensor for detecting an operation amount of an accelerator pedal, an operation amount of a brake pedal, a steering angle of a steering wheel, an engine speed, a rotational speed of a wheel, or the like. The drive system control unit 7100 performs arithmetic processing using a signal input from the vehicle state detection portion 7110, and controls an internal combustion engine, a drive motor, an electric power steering device, a brake device, and the like.

The vehicle body system control unit 7200 controls the operation of various devices provided in the vehicle body according to various programs. For example, the vehicle body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as a headlight, a back-up lamp, a brake lamp, a turn signal, a fog lamp, or the like. In this case, radio waves emitted from a mobile device as a substitute of a key or signals of various switches may be input to the vehicle body system control unit 7200. The vehicle body system control unit 7200 receives these input radio waves or signals, and controls a door lock device, a power window device, a lamp, and the like of the vehicle.

The battery control unit 7300 controls a secondary battery 7310 as a power source for driving the motor according to various programs. For example, the battery control unit 7300 receives an input of information about a battery temperature, a battery output voltage, a remaining charge amount in the battery, and the like from a battery device including the secondary battery 7310. The battery control unit 7300 performs arithmetic operation processing using these signals, and performs control for adjusting the temperature of the secondary battery 7310 or control a cooling device or the like included in the battery device.

The outside-vehicle information detection unit 7400 detects information outside the vehicle to which the vehicle control system 7000 is mounted. For example, at least one of the imaging section 7410 and the outside-vehicle information detecting section 7420 is connected to the outside-vehicle information detecting unit 7400. The imaging part 7410 includes at least one of a time-of-flight (ToF) camera, a stereoscopic camera, a monocular camera, an infrared camera, and other cameras. The outside-vehicle information detection section 7420 includes, for example, at least an environmental sensor for detecting a current atmospheric condition or weather condition, or an outside-vehicle information detection sensor for detecting other vehicles, obstacles, pedestrians, and the like in the periphery of the vehicle in which the vehicle control system 7000 is mounted.

For example, the environmental sensor may be at least one of a raindrop sensor that detects rain, a fog sensor that detects fog, a sun light sensor that detects the degree of sunlight, and a snow sensor that detects snowfall. The peripheral information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR device (light detection and distance measurement device, or laser imaging detection and distance measurement device). Each of the imaging portion 7410 and the off-vehicle information detecting portion 7420 may be provided as an independent sensor or device, or may be provided as a device in which a plurality of sensors or devices are integrated.

Here, fig. 19 shows an example of mounting positions of the imaging section 7410 and the outside-vehicle information detecting section 7420. The imaging portions 7910, 7912, 7914, 7916 and 7918 are provided at least one of positions on a front nose, a side view mirror, a rear bumper and a rear door of the vehicle 7900 and a position of an upper portion of a windshield in the vehicle, for example. The imaging portion 7910 provided at the front nose and the imaging portion 7918 provided at the upper portion of the windshield in the vehicle each mainly obtain an image of the front of the vehicle 7900. The imaging portions 7912 and 7914 provided at the side view mirror each mainly obtain an image of the side of the vehicle 7900. The imaging portion 7916 provided at the rear bumper or the rear door mainly obtains an image of the rear of the vehicle 7900. The imaging portion 7918 provided at an upper portion of a windshield in a vehicle is mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, and the like.

Note that fig. 19 shows an example of an imaging range of each of the imaging sections 7910, 7912, 7914, and 7916. The imaging range a indicates the imaging range of the imaging section 7910 provided at the anterior nose. The imaging ranges b and c represent the imaging ranges of the imaging portions 7912 and 7914 provided at the side view mirror, respectively. The imaging range d represents the imaging range of the imaging portion 7916 provided at the rear bumper or the rear door. For example, by superimposing the image data obtained by the imaging sections 7910, 7912, 7914, and 7916, a bird's eye image of the vehicle 7900 viewed from above can be obtained.

The vehicle exterior information detection portions 7920, 7922, 7924, 7926, 7928, 7930 provided in front of, behind, sideways of, at corners of, and above the windshield in the vehicle 7900 may be, for example, ultrasonic sensors or radar devices. The vehicle outside information detection portions 7920, 7926, and 7930 provided at the upper portion of a windshield in the vehicle, such as a front nose, a rear bumper, and a rear door of the vehicle 7900, may be LIDAR devices, for example. These outside-vehicle information detection sections 7920 to 7930 are mainly used for detecting preceding vehicles, pedestrians, obstacles, and the like.

The description continues with reference back to fig. 18. The vehicle exterior information detection unit 7400 causes the imaging portion 7410 to capture an image of the outside of the vehicle and receives the obtained image data. The outside-vehicle information detection unit 7400 receives detection information from the outside-vehicle information detection unit 7420 connected to the outside-vehicle information detection unit 7400. In the case where the outside-vehicle information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the outside-vehicle information detection unit 7400 transmits ultrasonic waves, electromagnetic waves, or the like, and receives information of the received reflected waves. The outside-vehicle information detection unit 7400 may perform a process of detecting an object such as a person, a vehicle, an obstacle, a sign, a character on a road surface, or a process of detecting a distance thereof based on the received information. The outside-vehicle information detection unit 7400 may perform an environment recognition process that recognizes rainfall, fog, road surface condition, or the like based on the received information. The off-vehicle information detection unit 7400 may calculate a distance to an object outside the vehicle based on the received information.

In addition, the outside-vehicle information detection unit 7400 may perform image recognition processing for recognizing a person, a vehicle, an obstacle, a sign, characters on a road surface, or the like or processing for detecting a distance thereof based on the received image data. The in-vehicle information detection unit 7400 may subject the received image data to processing such as distortion correction, alignment, and the like, and combine the image data captured by the plurality of different imaging sections 7410 to generate a bird's-eye image or a panoramic image. The outside-vehicle information detection unit 7400 may perform viewpoint conversion processing using image data captured by the different imaging section 7410.

The in-vehicle information detection unit 7500 detects information about the inside of the vehicle. For example, a driver state detection portion 7510 that detects the state of the driver is connected to the in-vehicle information detection unit 7500. The driver state detection portion 7510 may include a camera that images the driver, a biosensor that detects biological information about the driver, a microphone that collects sounds in the vehicle, and the like. The biosensor is provided, for example, in a seat surface, a steering wheel, or the like, and detects biological information about an occupant sitting on the seat or a driver holding the steering wheel. Based on the detection information input from the driver state detection portion 7510, the in-vehicle information detection unit 7500 may calculate the fatigue of the driver or the concentration of the driver, or may determine whether the driver is dozing. The in-vehicle information detection unit 7500 may subject the collected sound signal to processing such as noise cancellation processing or the like.

The integrated control unit 7600 controls general operations in the vehicle control system 7000 according to various programs. The input 7800 is connected to the integrated control unit 7600. The input portion 7800 is implemented by, for example, a device such as a touch panel, a button, a microphone, a switch, a lever, or the like, which can be input-operated by an occupant. The integrated control unit 7600 may be supplied with data obtained by recognizing voice input through a microphone. The input 7800 may be, for example, a remote control device using infrared rays or other radio waves, or an external connection device such as a mobile phone, a Personal Digital Assistant (PDA), or the like, which supports the operation of the vehicle control system 7000. The input 7800 may be, for example, a camera. In this case, the occupant may input information through a gesture. Alternatively, data obtained by detecting the movement of a wearable device worn by an occupant may be input. The input unit 7800 may include, for example, an input control circuit or the like that generates an input signal based on information input by an occupant or the like using the input unit 7800 and outputs the generated input signal to the integrated control unit 7600. The operation input unit 7800 such as an occupant inputs various data to the vehicle control system 7000 or instructs execution of a processing operation.

The storage 7690 may include a Read Only Memory (ROM) storing various programs to be executed by the microcomputer and a Random Access Memory (RAM) storing various parameters, operation results, sensor values, and the like. In addition, the storage portion 7690 may be implemented by a magnetic storage device such as a Hard Disk Drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

The general communication I/F7620 is a general communication I/F that mediates communication with various devices existing in the external environment 7750. The general communication I/F7620 may implement a cellular communication protocol such as a global system for mobile communications (GSM (registered trademark)), wiMAX (registered trademark), long term evolution (LTE (registered trademark)) or LTE-advanced (LTE-a) or some other wireless communication protocol such as a wireless LAN (also referred to as wireless fidelity (Wi-Fi (registered trademark)) or bluetooth (registered trademark)), the general communication I/F7620 may be connected to a device (e.g., an application server or a control server) existing in an external network (e.g., the internet, a cloud network or a company-specific network), for example, via a base station or an access point.

The dedicated communication I/F7630 is a communication I/F that supports development of a communication protocol for use in a vehicle. The dedicated communication I/F7630 may, for example, implement a standard protocol such as wireless access in a vehicle environment (WAVE), which is a combination of IEEE 802.11p as a lower layer and IEEE 1609 as an upper layer, dedicated Short Range Communication (DSRC), or a cellular communication protocol. The private communication I/F7630 typically performs V2X communication as a concept including one or more of the following: communication between vehicles (vehicle-to-vehicle), road-to-vehicle (vehicle-to-infrastructure), vehicle-to-home (vehicle-to-home), and pedestrian-to-vehicle (vehicle-to-pedestrian).

The positioning portion 7640 performs positioning by receiving a Global Navigation Satellite System (GNSS) signal from a GNSS satellite (a GPS signal from a GPS satellite), for example, and generates position information including latitude, longitude, and altitude of the vehicle. Note that the positioning section 7640 may recognize the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, a Personal Handyphone System (PHS), or a smart phone having a positioning function.

The beacon receiving portion 7650 receives, for example, radio waves or electromagnetic waves transmitted from a radio station installed on a road or the like, and thus, obtains information on the current position, congestion, a closed road, a required time, and the like. Note that the function of the beacon receiving portion 7650 may be included in the above-described dedicated communication I/F7630.

The in-vehicle device I/F7660 is a communication interface that mediates connection between the microcomputer 7610 and various in-vehicle devices 7760 existing in the vehicle. The in-vehicle device I/F7660 may establish wireless connection using a wireless communication protocol such as wireless LAN, bluetooth (registered trademark), near Field Communication (NFC), or Wireless Universal Serial Bus (WUSB). Further, the in-vehicle device I/F7660 may establish a cable connection such as a Universal Serial Bus (USB), a high-definition multimedia interface (HDMI (registered trademark)), a mobile high-definition link (MHL), or the like via a connection terminal (and a cable if necessary) not shown in the figure. The in-vehicle device 7760 may include, for example, at least one of a mobile device and a wearable device owned by an occupant, and an information device carried by or attached to the vehicle. The in-vehicle device 7760 may further include a navigation device that searches for a path to a desired destination. The in-vehicle device I/F7660 exchanges control signals or data signals with these in-vehicle devices 7760.

The in-vehicle network I/F7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I/F7680 transmits and receives signals and the like according to a predetermined protocol supported by the communication network 7010.

The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information obtained via at least one of the general-purpose communication I/F7620, the dedicated communication I/F7630, the positioning portion 7640, the beacon receiving portion 7650, the in-vehicle device I/F7660, and the in-vehicle network I/F7680. For example, the microcomputer 7610 may calculate a control target value of the driving force generating device, the steering mechanism, or the braking device based on the obtained information about the inside and outside of the vehicle, and output a control command to the driving system control unit 7100. For example, the microcomputer 7610 may perform cooperative control aimed at realizing functions of an Advanced Driver Assistance System (ADAS) including anti-collision or shock absorption for a vehicle, following driving based on a following distance, maintaining a vehicle speed of driving, warning of a collision of a vehicle, warning of a deviation of a vehicle from a lane, and the like. In addition, the microcomputer 7610 can execute cooperative control for performing an autonomous operation for autonomously running the vehicle without depending on the operation of the driver by controlling the driving force generating device, the steering mechanism, the braking device, and the like based on the obtained information about the surroundings of the vehicle.

The microcomputer 7610 may generate three-dimensional distance information between the vehicle and an object such as a surrounding structure, a person, or the like based on information obtained via at least one of the general communication I/F7620, the private communication I/F7630, the positioning portion 7640, the beacon receiving portion 7650, the in-vehicle device I/F7660, and the in-vehicle network I/F7680, and generate local map information including information about the surroundings of the current position of the vehicle. Further, the microcomputer 7610 may predict a danger such as a collision with a vehicle, approach of a pedestrian or the like, entry into a closed road or the like based on the obtained information, and generate a warning signal. The warning signal may be, for example, a signal for generating a warning sound or illuminating a warning light.

The audio/video output portion 7670 transmits an output signal of at least one of the audio and the video to an output device capable of visually or audibly transmitting an information notification to an occupant of the vehicle or the outside of the vehicle. In the example of fig. 18, an audio speaker 7710, a display portion 7720, and an instrument panel 7730 are shown as output devices. The display section 7720 may include, for example, at least one of an on-board display and a head-up display. The display section 7720 may have an Augmented Reality (AR) display function. The output device may be different from these devices and may be some other device such as a headset or a wearable device like a glasses-type display worn by an occupant or the like, a projector, or a light. In the case where the output device is a display device, the display device visually displays results obtained by various processes performed by the microcomputer 7610 or information received from another control unit in various forms (such as text, images, tables, graphics, and the like). Further, in the case where the output device is an audio output device, the audio output device converts an audio signal formed using reproduced audio data, sound data, or the like into an analog signal, and outputs the analog signal audibly.

Note that in the example shown in fig. 18, at least two control units connected to each other via the communication network 7010 may be integrated as one control unit. Alternatively, each individual control unit may comprise a plurality of control units. Further, the vehicle control system 7000 may include other control units not shown in the drawings. In addition, some or all of the functions to be performed by one of the control units in the above description may be allocated to some other control unit. That is, as long as information is transmitted and received via the communication network 7010, predetermined arithmetic processing can be performed by any control unit. Likewise, a sensor or device connected to one of the control units may be connected to the other control unit, and a plurality of control units may mutually transmit and receive detection information via the communication network 7010.

In the vehicle control system 7000, the semiconductor laser device of the present technology can be applied to, for example, an off-vehicle information detection unit.

Note that the present technology may also have the following configuration.

(1)

A control apparatus comprising:

The control circuit includes:

(2)

The control device according to (1), wherein,

The first control circuit includes a first current source connected to the electrode of the light emitting unit and a first switching element for switching on and off the operation of the first current source, and

The second control circuit includes a second current source connected to the electrode of the light emitting unit and a second switching element that turns on and off the operation of the second current source.

(3)

The control device according to (2), wherein,

The first switching element is turned on when the second switching element is turned on.

(4)

The control device according to (3), wherein,

When only the first switching element is turned on, light of the first polarization direction is emitted from the light emitting unit, and

When the first switching element and the second switching element are turned on, the polarization direction of light emitted from the light emitting unit is switched from the first polarization direction to the second polarization direction.

(5)

The control device according to any one of (1) to (4), wherein,

The control circuit is connected to the plurality of light emitting units.

(6)

A control method, comprising:

controlling a current flowing into the light emitting unit by a control circuit;

Controlling, by a first control circuit included in the control circuit, a current flowing into the light emitting unit so that a polarization direction of light emitted from the light emitting unit is a first polarization direction; and

The current flowing into the light emitting unit is controlled by a second control circuit included in the control circuit to switch the polarization direction of light emitted from the light emitting unit from a first polarization direction to a second polarization direction different from the first polarization direction.

(7)

A semiconductor laser device comprising:

A light emitting unit;

A polarizer, wherein,

The control circuit includes:

(8)

The semiconductor laser device according to (7), wherein,

The second control circuit includes a second current source connected to the electrode of the light emitting unit and a first switching element that turns on and off the operation of the second current source.

(9)

The semiconductor laser device according to (8), wherein,

(10)

The semiconductor laser device according to (9), wherein,

(11)

The semiconductor laser device according to any one of (7) to (10), comprising:

a plurality of light emitting units, wherein,

The control circuit is connected to the plurality of light emitting units.

(12)

The semiconductor laser device according to any one of (7) to (11), wherein,

The light of the first polarization direction is light of a fundamental transverse mode and the light of the second polarization direction is light of a higher order transverse mode.

(13)

The semiconductor laser device according to any one of (7) to (12), wherein,

The light emitting unit includes a mesa portion in which a lateral mode adjustment portion is formed, and an oxidation portion is formed at a side portion of the mesa portion.

(14)

The semiconductor laser device according to any one of (7) to (12), wherein,

The light emitting unit includes a table surface portion,

A first graded structure having a plurality of grooves arranged in a first direction is provided at the emission center portion of the mesa portion, and

A second taper structure having a plurality of grooves arranged in a second direction is provided at an emission peripheral portion of the mesa portion.

(15)

The semiconductor laser device according to (14), wherein,

The first direction is a direction orthogonal to the second direction.

(16)

A distance measuring device comprising the semiconductor laser device according to any one of (7) to (15).

(17)

An in-vehicle apparatus comprising the distance measuring apparatus according to (16).

List of reference marks

10. Semiconductor laser device

20、20A、20B VCSEL

21. Table surface portion

30. Control device

31. First control circuit

32. Second control circuit

40. Polarizer

70. Lateral mode adjustment layer

312. 322 Switching elements.

Claims

1. A control apparatus comprising:

The control circuit includes:

And a second control circuit controlling a current flowing into the light emitting unit to switch a polarization direction of light emitted from the light emitting unit from the first polarization direction to a second polarization direction different from the first polarization direction.

2. The control device according to claim 1, wherein,

The first control circuit includes a first current source connected to an electrode of the light emitting unit and a first switching element that turns on and off operations of the first current source, and the second control circuit includes a second current source connected to an electrode of the light emitting unit and a second switching element that turns on and off operations of the second current source.

3. The control device according to claim 2, wherein,

The second switching element is turned on when the first switching element is turned on.

4. The control device according to claim 3, wherein,

When the first and second switching elements are turned on, a polarization direction of light emitted from the light emitting unit is switched from the first polarization direction to the second polarization direction.

5. The control device according to claim 1, wherein,

The control circuit is connected to a plurality of the light emitting units.

6. A control method, comprising:

The current flowing into the light emitting unit is controlled by a second control circuit included in the control circuit to switch the polarization direction of light emitted from the light emitting unit from the first polarization direction to a second polarization direction different from the first polarization direction.

7. A semiconductor laser device comprising:

A light emitting unit;

A polarizer, wherein,

The control circuit includes:

A second control circuit that controls a current flowing into the light emitting unit to switch a polarization direction of light emitted from the light emitting unit from the first polarization direction to a second polarization direction different from the first polarization direction, and

The polarizer blocks light of the first polarization direction and transmits light of the second polarization direction.

8. The semiconductor laser device according to claim 7, wherein,

The first control circuit includes a first current source connected to an electrode of the light emitting unit and a first switching element that turns on and off an operation of the first current source, and the second control circuit includes a second current source connected to an electrode of the light emitting unit and a first switching element that turns on and off an operation of the second current source.

9. The semiconductor laser device according to claim 8, wherein,

10. The semiconductor laser device according to claim 9, wherein,

11. The semiconductor laser device according to claim 7, further comprising:

A plurality of the light emitting units, wherein,

The control circuit is connected to a plurality of the light emitting units.

12. The semiconductor laser device according to claim 7, wherein,

13. The semiconductor laser device according to claim 7, wherein,

14. The semiconductor laser device according to claim 7, wherein,

The light emitting unit includes a stage surface portion,

A first gradation structure having a plurality of grooves arranged in a first direction is provided at an emission center portion of the mesa portion, and

A second gradation structure having a plurality of grooves arranged in a second direction is provided at an emission peripheral portion of the mesa portion.

15. The semiconductor laser device according to claim 14, wherein,

The first direction is a direction orthogonal to the second direction.

16. A distance measuring device comprising the semiconductor laser device according to claim 7.

17. An in-vehicle apparatus comprising the distance measuring apparatus according to claim 16.