Laser array and laser radar

Abstract

Embodiments of the present application relate to the technical field of optical sensing, and provide a laser array and a laser radar. The differential resistance of the laser array is adjustable, and the optical power of output emitted laser light is adjustable. The laser array comprises a first laser and a second laser; the first laser comprises a first reflecting layer, a first active layer, and a second reflecting layer which are sequentially arranged in an epitaxial direction, and a first oxidation hole is formed in the second reflecting layer; the second laser comprises a third reflecting layer, a second active layer, and a fourth reflecting layer which are sequentially arranged in the epitaxial direction, a second oxidation hole is formed in the fourth reflecting layer, a light blocking layer is further provided on the side of the fourth reflecting layer away from the second active layer, and the projection of the light blocking layer on the second active layer overlaps the projection of the second oxidation hole on the second active layer; the first laser is electrically connected to the second laser.

Description

Laser arrays and lidar

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on October 12, 2023, with application number 202311326329.2 and application name “Laser Array and LiDAR”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of optical perception technology, and in particular to a laser array and a laser radar. Background Art

[0003] Currently, automated control equipment, including driverless cars and robot vacuums, is rapidly developing. These devices utilize sensing systems to perceive their surroundings and then make control decisions based on these surroundings. LiDAR (light detection and ranging) is a type of sensing system. LiDAR transmits laser light, which is then reflected by obstacles. The LiDAR receives the reflected laser light and determines the obstacle's location based on the transmitted and reflected laser light.

[0004] Existing lidars usually include a laser array, which is specifically used to output transmitted lasers. Among them, the laser array includes one or more lasers, and multiple lasers are connected in parallel. When the number of lasers included in the laser array is large, the differential resistance of the laser array is small, and the optical power of the transmitted laser output by the laser array is large, but the optical power of the transmitted laser output by the laser array is not adjustable. In other scenarios, the laser array only needs to include a small number of lasers that output transmitted lasers with small optical power. Since the number of lasers included in the laser array is reduced, the differential resistance of the laser array will increase, and it is difficult to reduce the differential resistance.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a laser array and a laser radar, wherein the differential resistance of the laser array is adjustable and the optical power of the output laser is adjustable.

[0007] In a first aspect, a laser array is provided, comprising a first laser and a second laser. The first laser comprises a first reflective layer, a first active layer, and a second reflective layer sequentially arranged along an epitaxial direction, wherein a first oxide hole is provided in the second reflective layer. The second laser comprises a third reflective layer, a second active layer, and a fourth reflective layer sequentially arranged along the epitaxial direction, wherein a second oxide hole is provided in the fourth reflective layer. A light-blocking layer is further provided on a side of the fourth reflective layer remote from the second active layer, wherein a projection of the light-blocking layer on the second active layer overlaps a projection of the second oxide hole on the second active layer. The first laser and the second laser are electrically connected. In the laser array, the first laser comprises a first reflective layer, a first active layer, and a second reflective layer sequentially arranged along the epitaxial direction, wherein a first oxide hole is provided in the second reflective layer. When the laser array receives a voltage or current, the voltage or current is transmitted to the first laser, energizing the first laser. As a result, the first active layer of the first laser generates a first photon, which oscillates in a resonant cavity formed by the first and second reflective layers, thereby generating a first laser beam that is output through the first oxide hole. The second laser includes a third reflective layer, a second active layer, and a fourth reflective layer sequentially arranged along the epitaxial direction. A second oxide hole is provided in the fourth reflective layer. A light-blocking layer is further provided on a side of the fourth reflective layer away from the second active layer. The projection of the light-blocking layer on the second active layer overlaps with the projection of the second oxide hole on the second active layer. When the laser array receives a voltage or current, the voltage or current can be transmitted to the second laser, causing the second laser to be powered. As a result, the second active layer of the second laser generates a second photon, which oscillates in the resonant cavity formed by the third reflective layer and the fourth reflective layer, thereby generating a second laser. The second laser is transmitted through the second oxide hole to the light-blocking layer, which blocks the output of the second laser or partially outputs the second laser. The emitted lasers output by the laser array are specifically the first laser and the second laser. When the first laser and the second laser are connected in parallel and the laser array receives a constant voltage, the differential resistance of the first laser and the second laser in parallel is lower than the differential resistance of the first laser; when the first laser and the second laser are connected in parallel and the laser array receives a constant current, the optical power of the emitted laser light output by the laser array will change; when the first laser and the second laser are connected in series and the laser array receives a constant voltage, the optical power of the emitted laser light output by the laser array will change. In other words, when the laser array includes a second laser, the differential resistance of the laser array is adjustable, and the optical power of the emitted laser light output is adjustable.

[0008] Optionally, the laser array includes multiple first lasers and at least one second laser; multiple first lasers are connected in parallel; at least one first laser is electrically connected to any second laser. In this optional manner, the laser array may specifically include M first lasers and N second lasers, M is a positive integer greater than or equal to 2, N is a positive integer greater than or equal to 1, and the M first lasers are connected in parallel, the N second lasers are connected in parallel, and the first laser and the second laser are connected in parallel. Assume that the differential resistance of the first laser and the second laser is approximately equal, denoted as R s , then when the laser array receives a fixed voltage, the differential resistance of the laser array R=R s / (M+N), it can be seen that when the number of second lasers increases, the differential resistance of the laser array will decrease. The differential resistance of the laser array can be adjusted by adjusting the number of second lasers.

[0009] Optionally, the laser array includes one or more first regions; the first region includes a second laser; at least one first laser is connected in parallel with the second laser in the first region; the second lasers in any two first regions are electrically isolated, and the second lasers in any two first regions are connected in parallel. In this optional method, it is assumed that the laser array includes M first lasers and X first regions, and one first region includes Y second lasers, X is a positive integer greater than or equal to 1, and Y is a positive integer greater than or equal to 1. Since at least one first laser is connected in parallel with the second laser in the first region, when the laser array receives a fixed voltage and all lasers are working, the optical power of the lasers output by the multiple first lasers does not change. And the differential resistance R of the laser array is R = R s / (M+X×Y), it can be seen that when X increases and / or Y increases, the differential resistance of the laser array will decrease; when X decreases and / or Y decreases, the differential resistance of the laser array will increase. When the laser array receives a fixed current I0 and all lasers are operating, since multiple first lasers are connected in parallel, at least one first laser is connected in parallel with the second laser in the first region, and multiple second lasers are connected in parallel, the current flowing through the M first lasers is I = M×I0 / (M+X×Y). Based on the relationship between power and current, ΔP = ΔI×SE, where SE is the slope efficiency, ΔI is the change in current flowing through the M first lasers, and ΔP is the change in optical power of the lasers output by the M first lasers in parallel. It can be seen that when X increases and / or Y increases, the current I flowing through the M first lasers decreases, and the optical power of the lasers output by the M first lasers in the laser array will decrease; when X decreases and / or Y decreases, the current I flowing through the M first lasers increases, and the optical power of the lasers output by the M first lasers in the laser array will increase.

[0010] Optionally, the laser array includes one or more first regions; the first region includes a second laser; at least one first laser is connected in series with the second laser in the first region; the second lasers in any two first regions are electrically isolated, and the second lasers in any two first regions are connected in parallel. In this optional method, it is assumed that the laser array includes M first lasers and X first regions, and one first region includes Y second lasers, where X is a positive integer greater than or equal to 1, and Y is a positive integer greater than or equal to 1. The differential resistance of the first laser and the second laser is approximately equal, denoted as R s , and the laser array receives a fixed current, and when all lasers are working, since the first laser is connected in series with the second laser in the first area, multiple first lasers are connected in parallel, and any two second lasers in the first area are connected in parallel, the optical power of the laser output by the first laser does not change, and the differential resistance R of the laser array is R s / M+R s / (X×Y), it can be seen that when X increases and / or Y increases, the differential resistance of the laser array will decrease; when X decreases and / or Y decreases, the differential resistance of the laser array will increase. When the laser array receives a fixed voltage V0 and all lasers are working, since the first laser is connected in series with the second laser in the first area, multiple first lasers are connected in parallel, and any two second lasers in the first area are connected in parallel, the voltage V distributed to the M first lasers = (X×Y)×V0 / (M+X×Y). According to the relationship between voltage and current, it can be seen that ΔV = ΔI*R s / M, where ΔV is the change in voltage distributed to the M parallel first lasers, and ΔI is the change in current flowing through the M first lasers. ΔV=ΔI*R s Dividing the left and right sides of the equal sign of / M and ΔP=ΔI×SE respectively, we can get ΔP=ΔV×SE×M / R s It can be seen that when X increases and / or Y increases, the optical power of the lasers output by the M first lasers in the laser array will increase; when X decreases and / or Y decreases, the optical power of the emitted lasers output by the M first lasers in the laser array will decrease.

[0011] Optionally, the laser array further includes a second region; the second region includes a plurality of first lasers; and the first lasers in the second region are electrically isolated from the second lasers in any one of the first regions.

[0012] Optionally, the second region is further provided with one or more second lasers, and the first lasers and the second lasers in the second region are connected in parallel.

[0013] Optionally, the first region includes a plurality of second lasers, and the plurality of second lasers are connected in parallel.

[0014] Optionally, the laser array is configured to receive a fixed voltage.

[0015] Optionally, the laser array is configured to receive a fixed current.

[0016] Optionally, the first laser further includes a first substrate disposed on a side of the first reflective layer away from the first active layer, a first negative electrode disposed on a side of the first substrate away from the first active layer, and a first positive electrode disposed on a side of the second reflective layer away from the first active layer; or, the first laser further includes a first substrate disposed on a side of the first reflective layer away from the first active layer, a first conductive layer disposed between the first substrate and the first reflective layer, a first negative electrode in contact with the first conductive layer, and a first positive electrode disposed on a side of the second reflective layer away from the first active layer.

[0017] Optionally, the second laser further includes a second substrate arranged on a side of the third reflective layer away from the second active layer, a second negative electrode arranged on a side of the second substrate away from the second active layer, and a second positive electrode arranged on a side of the fourth reflective layer away from the second active layer; or, the second laser further includes a second substrate arranged on a side of the third reflective layer away from the second active layer, a second conductive layer arranged between the second substrate and the third reflective layer, a second negative electrode in contact with the second conductive layer, and a second positive electrode arranged on a side of the fourth reflective layer away from the second active layer.

[0018] In a second aspect, a laser radar is provided, comprising a driving device and a laser array as described in any one of the first aspects above; the driving device is used to input a fixed voltage or a fixed current to the laser array.

[0019] Optionally, the laser array includes one or more first areas; a driving device, used to receive an input signal and control the input of a fixed voltage or a fixed current to the n first areas according to the input signal, where the input signal is an input signal received by the laser radar, and n is an integer greater than or equal to 0.

[0020] Optionally, the laser array includes one or more first regions; a driving device is used to receive a feedback signal and control the input of a fixed voltage or a fixed current to the n first regions according to the feedback signal, where n is an integer greater than or equal to 0.

[0021] Optionally, the laser radar also includes a receiving device and a signal processing device; the receiving device is used to receive reflected laser light, generate a receiving signal, and transmit the receiving signal to the signal processing device; the emitted laser light is reflected after encountering an obstacle to form a reflected laser light; the signal processing device is used to generate the feedback signal based on the receiving signal.

[0022] Optionally, the signal processing device is further used to determine the distance between the obstacle and the laser radar based on the received signal.

[0023] Among them, the technical effects brought about by any possible implementation method of the second aspect can refer to the technical effects brought about by the different implementation methods of the above-mentioned first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic diagram of the structure of a laser radar provided in an embodiment of the present application;

[0025] FIG2 is a schematic structural diagram of a laser array provided in an embodiment of the present application;

[0026] FIG3 is a schematic diagram showing how the optical power of reflected laser light received by a receiving device according to an embodiment of the present application varies with the distance between an obstacle and a laser radar;

[0027] FIG4 is a schematic structural diagram of a laser array provided in another embodiment of the present application;

[0028] FIG5 is a schematic diagram of driving electrical pulses for driving different numbers of vertical cavity surface emitting lasers to output laser light according to an embodiment of the present application;

[0029] FIG6 is a schematic structural diagram of a laser array provided in yet another embodiment of the present application;

[0030] FIG7 is a schematic structural diagram of a first laser in a laser array provided in yet another embodiment of the present application;

[0031] FIG8 is a schematic structural diagram of a second laser in a laser array provided in another embodiment of the present application;

[0032] FIG9 is a schematic structural diagram of a laser array provided in yet another embodiment of the present application;

[0033] FIG10 is a cross-sectional view 1 along line AA′ of FIG9 ;

[0034] FIG11 is a second cross-sectional view along line AA′ of FIG9 ;

[0035] FIG12 is a schematic structural diagram of a laser array provided in yet another embodiment of the present application;

[0036] FIG13 is a cross-sectional view along line BB' of FIG12;

[0037] FIG14 is a cross-sectional view 1 along CC' of FIG12;

[0038] FIG15 is a schematic structural diagram of a laser array provided in another embodiment of the present application;

[0039] FIG16 is a schematic structural diagram of a laser array provided in yet another embodiment of the present application;

[0040] FIG17 is a cross-sectional view along line DD' of FIG16;

[0041] FIG18 is a cross-sectional view 1 along line EE' of FIG16;

[0042] FIG19 is a schematic structural diagram of a laser array provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0044] Unless otherwise defined, all scientific and technological terms used herein have the same meaning as those known to those of ordinary skill in the art. In the embodiments of the present application, "at least one" refers to one or more, and "a plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, wherein A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following items" or its similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can represent: a, b, c, a and b, a and c, b and c or a, b and c, wherein a, b and c can be single or multiple. In addition, in the embodiments of the present application, words such as "first" and "second" do not limit quantity and order.

[0045] In addition, in the embodiments of the present application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to changes in the orientation of the components in the drawings.

[0046] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being more preferred or advantageous than other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0047] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0048] Currently, automated control equipment, including driverless cars and robot vacuums, is rapidly developing. These devices rely on built-in perception systems to sense their surroundings and then make decisions based on those surroundings. Light detection and ranging (LIDAR) is one type of perception system.

[0049] For example, lidar can be used as vehicle-mounted lidar, airborne lidar, etc. installed in driverless cars, wherein the lidar is used to detect the distance between the driverless car and the surrounding objects (obstacles) of the driverless car, and the driverless car performs control actions such as braking avoidance and turning according to the distance measured by the lidar.

[0050] In addition, the laser radar can also be installed in a sweeping robot, where the laser radar is used to detect the distance between the sweeping robot and the furniture (obstacles) around the sweeping robot. The sweeping robot performs control actions such as turning and deceleration based on the distance measured by the laser radar.

[0051] 1 , an embodiment of the present application provides a schematic structural diagram of a laser radar 10, wherein the laser radar 10 includes a laser array 11 and a driving device 12. The driving device 12 is used to drive the laser array 11 to output an emission laser. The emission laser is transmitted to an obstacle. The obstacle can be any object around the laser radar 10. The emission laser is reflected after being transmitted to the surface of the obstacle.

[0052] A reflected laser is generated, and the laser radar 10 receives the reflected laser and determines the distance L between the laser radar 10 and the obstacle based on the transmitted laser and the reflected laser.

[0053] Exemplarily, the laser radar 10 shown in FIG1 further includes a signal processing device 13 and a receiving device 14. Specifically, the receiving device 14 receives the reflected laser light, generates a received signal based on the reflected laser light, and transmits the received signal to the signal processing device 13. The signal processing device 13 is configured to determine the distance L between the laser radar 10 and the obstacle based on the received signal. The signal processing device 13 can determine the distance L between the laser radar 10 and the obstacle based on the principle of pulse time-of-flight (TOF), or based on the principle of frequency modulated continuous waveform (FMCW) coherence.

[0054] For example, when the signal processing device 13 determines the distance between the laser radar 10 and the obstacle based on the TOF principle, the signal processing device 13 receives the time when the laser array 11 outputs the emitted laser, and the receiving signal transmitted by the receiving device 14 to the signal processing device 13 includes the time when the receiving device 14 receives the reflected laser. Since the speed of light is fixed and known, the signal processing device 13 can determine the distance L between the laser radar 10 and the obstacle based on the difference between the time of outputting the emitted laser and the time of receiving the reflected laser.

[0055] Exemplarily, the driving device 12 often drives the laser array 11 to continuously output multiple transmitted lasers. For example, two adjacent transmitted lasers among the multiple transmitted lasers output by the laser array 11 are transmitted laser s1 and transmitted laser s2, wherein the laser array 11 outputs transmitted laser s1 at a first moment, and the receiving device 14 receives the reflected laser s1' formed by the transmitted laser s1 being transmitted to the obstacle and reflected. Subsequently, the laser array 11 outputs transmitted laser s2 at a second moment after the first moment, and the receiving device 14 receives the reflected laser s2' formed by the transmitted laser s2 being transmitted to the obstacle and reflected... When the laser array 11 continuously outputs several to tens of thousands of transmitted lasers in the same direction within one second, the receiving device 14 will receive several to tens of thousands of reflected lasers. In this way, the laser radar 10 can determine the distance between the obstacle and the laser radar 10 at different moments, and then determine the speed parameter of the obstacle. For example, when the laser array 11 continuously outputs several to tens of thousands of transmitted light beams in different directions within one second, the receiving device 14 will receive several to tens of thousands of reflected lasers. In this way, the laser radar 10 can determine the distance between different positions of the obstacle and the laser radar 10, and then determine the physical model of the obstacle.

[0056] For example, the existing laser array 11 typically includes a vertical-cavity surface-emitting laser (VCSEL). Compared to an edge-emitting laser (EEL), a VCSEL has the advantages of low cost, a small divergence angle of the output laser light, a low threshold current, a simple packaging process, and easy implementation of a two-dimensional integrated surface light source. However, the optical power of the laser light output by a VCSEL is limited. Therefore, in the existing laser array 11, multiple VCSELs are often connected in parallel to increase the optical power of the laser light output by the laser array 11.

[0057] When the number of vertical cavity surface emitting lasers included in the laser array 11 is fixed and the voltage or current received by the laser array 11 does not change, the optical power of the transmitted laser light output by the laser array 11 will also be fixed, and the optical power of the transmitted laser light output by the laser array 11 is not adjustable. When the distance between the obstacle and the laser radar 10 is relatively far, the laser array 11 needs to output a transmitted laser light with a relatively high optical power, so that the optical power of the reflected laser light received by the receiving device 14 is not less than the minimum optical power that the receiving device 14 can receive, thereby allowing the receiving device 14 to generate a received signal based on the reflected laser light. When the distance between the obstacle and the laser radar 10 is relatively close, if the optical power of the transmitted laser light output by the laser array 11 is still very high, the optical power of the reflected laser light received by the receiving device 14 may be greater than the maximum optical power that the receiving device 14 can receive, causing the reflected laser light received by the receiving device 14 to be saturated, thereby distorting the received signal generated by the receiving device 14.

[0058] Exemplarily, in order to change the optical power of the emitted laser light output by the laser array 11, the existing laser array 10 generally includes two different partitions, one partition outputting an emitted laser light with a larger optical power, and the other partition outputting an emitted laser light with a smaller optical power. Exemplarily, referring to FIG2 , FIG2 is a schematic structural diagram of a laser array 11 according to an embodiment of the present application, wherein the laser array 11 includes a partition A1 and a partition A2, wherein partition A1 includes 20 parallel vertical cavity surface emitting lasers, and partition A2 includes 10 parallel vertical cavity surface emitting lasers, and the vertical cavity surface emitting lasers in partition A2 are electrically isolated from the vertical cavity surface emitting lasers in partition A1. When the distance between the obstacle and the laser radar 10 is relatively far, the 20 parallel vertical cavity surface emitting lasers in partition A1 are selected to output the emitted laser light with a larger optical power; when the distance between the obstacle and the laser radar 10 is relatively close, the 10 parallel vertical cavity surface emitting lasers in partition A2 are selected to output the emitted laser light with a smaller optical power.

[0059] Referring to FIG3 , FIG3 is a schematic diagram showing how the optical power of the reflected laser received by the receiving device 14 according to an embodiment of the present application varies with the distance between the obstacle and the laser radar 10, wherein the horizontal axis in FIG3 represents the distance between the obstacle and the laser radar 10 in meters (m), and the vertical axis in FIG3 represents the optical power of the reflected laser received by the receiving device 14 in milliwatts (mW). In FIG3 , the maximum optical power that the receiving device 14 can receive is 1400 mW, and the minimum optical power that the receiving device 14 can receive is 80 mW. Referring to FIG3 , when the distance between the obstacle and the laser radar 10 is less than 3 m, the 10 parallel vertical cavity surface emitting lasers in partition A2 are selected to output the emitted laser. At this time, the optical power of the reflected laser received by the receiving device 14 decreases as the distance between the obstacle and the laser radar 10 increases, and the maximum optical power of the reflected laser received by the receiving device 14 is 1350 mW, and the minimum optical power of the reflected laser received by the receiving device 14 is 200 mW. When the distance between the obstacle and the laser radar 10 is greater than or equal to 3m, 20 parallel vertical cavity surface emitting lasers in partition A1 are selected to output the emitted laser. At this time, the optical power of the reflected laser received by the receiving device 14 decreases with the increase of the distance between the obstacle and the laser radar 10, and the maximum optical power of the reflected laser received by the receiving device 14 is 1380mW, and the minimum optical power of the reflected laser received by the receiving device 14 is 100mW.

[0060] In some embodiments, as shown in FIG4 , compared to the laser array 11 shown in FIG2 , the laser array 11 shown in FIG4 further includes a partition A3, which includes four parallel vertical cavity surface emitting lasers. Specifically, when the distance between the obstacle and the laser radar 10 is greater than or equal to 4 meters, the 20 parallel vertical cavity surface emitting lasers in partition A1 are selected to output laser light; when the distance between the obstacle and the laser radar 10 is greater than or equal to 1 meter and less than 4 meters, the 10 parallel vertical cavity surface emitting lasers in partition A2 are selected to output laser light; and when the distance between the obstacle and the laser radar 10 is less than 1 meter, the four parallel vertical cavity surface emitting lasers in partition A3 are selected to output laser light.

[0061] Exemplarily, the laser array 11 may include more partitions, and the number of vertical cavity surface emitting lasers included in each partition may be changed, so that the laser array 11 selects the vertical cavity surface emitting laser in any partition to output the emitting laser with a predetermined optical power according to the distance between the obstacle and the laser radar 10.

[0062] However, in the laser array 11 shown in FIG. 2 or FIG. 4 , different partition positions are different. When the laser array 11 is required to emit laser light to a predetermined position, an optical system with different parameters is required to transmit the laser light emitted from different partitions to the predetermined position, thereby making the design of the laser array 11 unnecessarily complicated.

[0063] In particular, in the partition design scheme, for a partition including a smaller number of vertical cavity surface emitting lasers, the reduction in the number of vertical cavity surface emitting lasers will increase the differential resistance of the partition. When the differential resistance of the partition increases, the fall time of the driving electric pulse that drives the vertical cavity surface emitting laser of the partition to output the emitted laser will become longer, and the period of the driving electric pulse will become longer, thereby lengthening the period of the partition outputting multiple pulsed lasers, affecting the detection rate of the lidar. Specifically, as shown in Figure 5, Figure 5 is a schematic diagram of the driving electric pulse for driving different numbers of vertical cavity surface emitting lasers to output the emitted laser provided by an embodiment of the present application. The horizontal axis in Figure 5 represents time, in microseconds (μs), and the vertical axis in Figure 5 represents the current size of the driving electric pulse, in milliamperes (mA). As shown in Figure 5, Curve 1 represents the driving electric pulse that drives 14 vertical cavity surface emitting lasers to output laser light in parallel. In Curve 1, the falling time of the driving electric pulse (the time from the falling edge of the driving electric pulse to the current of the driving electric pulse dropping to 0mA) is t1; Curve 2 represents the driving electric pulse that drives 9 vertical cavity surface emitting lasers to output laser light in parallel. In Curve 2, the falling time of the driving electric pulse is t2; Curve 3 represents the driving electric pulse that drives 2 vertical cavity surface emitting lasers to output laser light in parallel. In Curve 3, the falling time of the driving electric pulse is t3. As can be seen from Figure 5, t3>t2>t1. Among them, when driving the vertical cavity surface emitting laser to output two laser lights, the second driving electric pulse needs to appear after the current of the previous driving electric pulse drops to 0mA. Therefore, it can be seen from Figure 5 that when the number of VCSELs included in a region decreases, the differential resistance of the region will increase, the fall time of the driving electric pulse that drives the VCSELs in the region to output the emitted laser will become longer, and the period of the driving electric pulse will become longer, thereby making the period of the VCSELs in the region outputting multiple emitted lasers longer, which will ultimately affect the detection rate of the lidar.

[0064] Accordingly, an embodiment of the present application provides a laser array, the differential resistance of the laser array is adjustable, and the optical power of the output laser emission is adjustable.

[0065] Referring to Figure 6, Figure 6 is a structural schematic diagram of the laser array 20 provided in an embodiment of the present application, and (a) in Figure 6 is a top view of the laser array 20, which includes a laser 21 (also referred to as a first laser) and a laser 22 (also referred to as a second laser).

[0066] (b) in FIG6 is a cross-sectional view of the laser 21 in the laser array 20, wherein the laser 21 includes a reflective layer 211 (also referred to as a first reflective layer), an active layer 212 (also referred to as a first active layer), and a reflective layer 213 (also referred to as a second reflective layer) sequentially arranged along the epitaxial direction (the z-axis direction in FIG6), and an oxidation hole 214 (also referred to as a first oxidation hole) is provided in the reflective layer 213.

[0067] Exemplarily, the laser 21 is also called a semiconductor laser, specifically a vertical cavity surface emitting laser. The reflective layer 211 and the reflective layer 213 constitute the resonant cavity of the laser 21, and the active layer 212 constitutes the pump source of the laser 21. When the laser 21 is powered (receives current or voltage), the active layer 212 generates photons, which oscillate repeatedly in the resonant cavity formed by the reflective layer 211 and the reflective layer 213. The resonant cavity selects photons with a certain frequency and consistent direction for the highest priority amplification, while suppressing photons of other frequencies and directions, thereby generating laser light and outputting it through the oxidation hole 214. For example, after the active layer 212 generates photons, all photons that do not move along the axis of the resonant cavity (z-axis direction) quickly escape from the resonant cavity and no longer come into contact with the active layer 212. However, all photons that move along the axis of the resonant cavity continue to move forward in the cavity and, after being reflected by the reflective layer 211 and the reflective layer 213, continuously pass through the active layer 212 to generate stimulated radiation, thereby forming a strong light beam with the same propagation direction, frequency, and phase in the resonant cavity, that is, laser light. The laser light is output through the oxidized hole 214 in the reflective layer 213. The oxidized hole 214 can limit the transverse mode of the laser output by the laser 21 and the transverse distribution of the current density, and the size of the oxidized hole 214 determines whether the laser 21 is in a multi-transverse mode state or a single-transverse mode state. Exemplarily, the lateral distribution of current density specifically refers to the current density within the range of the oxidation aperture 214. When the size of the oxidation aperture 214 is small, the laser 21 can achieve a current density that reaches the threshold condition for photon generation in the active layer 212 when the received current or voltage is small, i.e., the threshold current or threshold voltage of the laser 21 is small. The differential resistance of the laser 21 is negatively correlated with the size of the oxidation aperture 214. Therefore, when the size of the oxidation aperture 214 is small, the differential resistance of the laser 21 is large and cannot be ignored. The reason why the threshold current or threshold voltage of the laser 21 needs to be small is that when the current received by the laser 21 is less than the threshold current or the voltage received by the laser 21 is less than the threshold voltage, the laser 21 converts the received current or voltage into Joule heat. When the threshold current or threshold voltage of the laser 21 is large, the Joule heat converted by the laser 21 will be large, and large Joule heat will affect the performance of the laser 21.

[0068] As shown in FIG6(b), the reflective layer 211 and the reflective layer 213 are made of a semiconductor material with a high reflectivity (e.g., a reflectivity of 99.9%). In some embodiments, the reflective layer 211 is formed by alternating epitaxial growth of a semiconductor material with a high refractive index and a semiconductor material with a low refractive index, while the reflective layer 213 is formed by alternating epitaxial growth of a semiconductor material with a high refractive index and a semiconductor material with a low refractive index. The reflective layer 213 can provide holes and the reflective layer 211 can provide electrons, or the reflective layer 213 can provide electrons and the reflective layer 211 can provide holes. The reflective layer 211 and the reflective layer 213 are used to provide electrons and holes (collectively referred to as carriers), respectively. The active layer 212 can be made of a semiconductor material with high optical gain, which can be a quantum well (QW) structure, so that carriers (e.g., electrons and holes) recombine in the active layer 212 to form photons and are emitted when stimulated by current or voltage.

[0069] As shown in FIG6( b ), the laser 21 further includes a substrate 215 (also referred to as a first substrate) disposed on a side of the reflective layer 211 away from the active layer 212. The projection of the active layer 212 on the substrate 215 is within the projection of the reflective layer 211 on the substrate 215. For example, the active layer 212 and the reflective layer 211 have the same size and shape, or the active layer 212 has a smaller size than the reflective layer 211. Specifically, the reflective layer 211 may be square and the active layer 212 may be circular, with the two layers having the same central axis. Alternatively, both the reflective layer 211 and the active layer 212 may be square and have exactly the same size and shape. Similarly, the projection of the reflective layer 213 on the substrate 215 is within the projection of the reflective layer 211 on the substrate 215.

[0070] In one embodiment, as shown in FIG6(b), the laser 21 further comprises a negative electrode 216 (also referred to as a first negative electrode) disposed on a side of the substrate 215 away from the active layer 212, and a positive electrode 217 (also referred to as a first positive electrode) disposed on a side of the reflective layer 213 away from the active layer 212. When the laser 21 is powered, the negative electrode 216 and the positive electrode 217 of the laser 21 receive a voltage or current to form a voltage difference, thereby causing the active layer 212 to generate photons. The projection of the positive electrode 217 on the substrate 215 does not overlap with the projection of the oxidation hole 214 on the substrate 215, and the substrate 215 is a conductive substrate. In some embodiments, the oxidation hole 214 is formed by forming a ring-shaped shallow trench isolation (STI) STI1, and then growing oxide inward from the inner wall of the ring-shaped STI1 to form the oxidation hole 214 of a predetermined size. The STI1 may be in the shape of a circular ring, thereby making the oxidation hole circular, or the STI1 may be in the shape of a polygonal ring, thereby making the oxidation hole polygonal. Along the z-axis, the STI1 penetrates the reflective layer 213 and the active layer 212 and contacts the reflective layer 211. Typically, after the STI1 is formed in the laser 21 and the oxidation hole 214 is made, an insulating material is deposited inside the STI1 and on the reflective layer 213 to form an insulating layer 218. Then, a pattern of the positive electrode 217 is formed on the insulating layer 218 by photolithography and etching processes, thereby making the positive electrode 217. An insulating layer 218 exists between the positive electrode 217 and the STI1, the positive electrode 217 contacts the reflective layer 213, and a portion of the insulating layer 218 exists in the area surrounded by the positive electrode 217. The projection of this portion of the insulating layer 218 on the active layer 212 covers the projection of the oxidation hole 214 on the active layer 212.

[0071] In another embodiment, as shown in FIG7 , the laser 21 further includes a conductive layer 210 (also referred to as a first conductive layer) disposed between a substrate 215 and a reflective layer 211, a negative electrode 216 in contact with the conductive layer 210, and a positive electrode 217 disposed on a side of the reflective layer 213 away from the active layer 212. When the laser 21 is powered, the negative electrode 216 and the positive electrode 217 of the laser 21 receive a voltage or current to form a voltage difference, thereby causing the active layer 212 to generate photons. The projection of the positive electrode 217 on the substrate 215 does not overlap with the projection of the oxide hole 214 on the substrate 215, and the substrate 215 is an insulating substrate. In some embodiments, the oxide hole 214 is formed by forming a ring-shaped shallow trench isolation (STI) STI1, and then growing oxide from the inner wall of the ring-shaped STI1 inward to form the oxide hole 214 of a predetermined size. The STI1 can be a circular ring, thereby making the oxidation hole circular, or the STI1 can be a polygonal ring, thereby making the oxidation hole polygonal. Along the z-axis, the STI1 penetrates the reflective layer 213 and the active layer 212 and contacts the reflective layer 211 (similar to the STI1 shown in (b) of FIG6 ). In some examples, the STI1 also penetrates the reflective layer 211 and contacts the conductive layer 210. Typically, after STI1 is formed in the laser 21 and the oxidation hole 214 is made, an insulating material is deposited inside the STI1 and on the reflective layer 213 to form an insulating layer 218, and then a pattern of the positive electrode 217 is made on the insulating layer 218 through photolithography and etching processes, thereby making the positive electrode 217, wherein an insulating layer 218 exists between the positive electrode 217 and the STI1, the positive electrode 217 is in contact with the reflective layer 213, and there is also a partial insulating layer 218 in the area surrounded by the positive electrode 217, and the projection of this partial insulating layer 218 on the active layer 212 covers the projection of the oxidation hole 214 on the active layer 212.

[0072] For example, as shown in FIG7 , regardless of whether the STI1 penetrates the reflective layer 213 and the active layer 212, or penetrates the reflective layer 213, the active layer 212, and the reflective layer 211, the negative electrode 216 in FIG7 may or may not be in contact with the reflective layer 211. For example, an insulating layer may be provided between the reflective layer 211 and the negative electrode 216 to prevent the negative electrode 216 from contacting the reflective layer 211. Alternatively, a predetermined spacing may be provided between the reflective layer 211 and the negative electrode 216 in the x-axis direction to prevent the negative electrode 216 from contacting the reflective layer 211.

[0073] (c) in FIG6 is a cross-sectional view of the laser 22 in the laser array 20; wherein the laser 22 includes a reflective layer 221 (also referred to as the third reflective layer), an active layer 222 (also referred to as the second active layer), and a reflective layer 223 (also referred to as the fourth reflective layer) sequentially arranged along the epitaxial direction (the z-axis direction in FIG6 ), an oxidation hole 224 (also referred to as the second oxidation hole) is provided in the reflective layer 223, and a light blocking layer 229 is further provided on the side of the reflective layer 223 away from the active layer 222, and the projection of the light blocking layer 229 on the active layer 222 overlaps with the projection of the oxidation hole 224 on the active layer 222.

[0074] Exemplarily, the laser 22 is also called a semiconductor laser, specifically a vertical cavity surface emitting laser. The reflective layer 221 and the reflective layer 223 constitute the resonant cavity of the laser 22, and the active layer 222 constitutes the pump source of the laser 22. When the laser 22 is powered (receives current or voltage), the active layer 222 generates photons, which oscillate repeatedly in the resonant cavity formed by the reflective layer 221 and the reflective layer 223. The resonant cavity selects photons with a certain frequency and consistent direction for the highest priority amplification, while suppressing photons of other frequencies and directions, thereby generating laser light and transmitting it to the light blocking layer 229 through the oxidation hole 224.

[0075] 6( c ), the projection of the light-blocking layer 229 on the active layer 222 overlaps the projection of the oxidized holes 224 on the active layer 222. Alternatively, the projection of the light-blocking layer 229 on the active layer 222 completely covers the projection of the oxidized holes 224 on the active layer 222, thereby blocking the laser light generated by the laser 22 and preventing the laser 22 from emitting laser light. Alternatively, the projection of the light-blocking layer 229 on the active layer 222 partially covers the projection of the oxidized holes 224 on the active layer 222, thereby partially blocking the laser light emitted by the laser 22 and preventing the laser light from emitting laser light. Alternatively, the projection of the light-blocking layer 229 on the active layer 222 partially covers the projection of the oxidized holes 224 on the active layer 222, thereby partially blocking the laser light emitted by the laser 22 and preventing the laser light from emitting ...

[0076] For example, the structure and function of the reflective layer 221 may refer to the structure and function of the reflective layer 211 , the structure and function of the active layer 222 may refer to the structure and function of the active layer 222 , and the structure and function of the reflective layer 223 may refer to the structure and function of the reflective layer 213 , which will not be repeated here.

[0077] As shown in (c) of FIG6 , the laser 22 further includes a substrate 225 (also referred to as a second substrate) disposed on a side of the reflective layer 221 away from the active layer 222. The projection of the active layer 222 on the substrate 225 is within the projection of the reflective layer 221 on the substrate 225. For example, the active layer 222 and the reflective layer 221 have the same size and shape, or the active layer 222 has a smaller size than the reflective layer 221. Specifically, the reflective layer 221 may be square and the active layer 222 may be circular, with the two layers having the same central axis. Alternatively, both the reflective layer 221 and the active layer 222 may be square and have exactly the same size and shape. Similarly, the projection of the reflective layer 223 on the substrate 225 is within the projection of the reflective layer 221 on the substrate 215.

[0078] In one embodiment, as shown in FIG6(c), the laser 22 further includes a negative electrode 226 (also referred to as a second negative electrode) disposed on a side of the substrate 225 away from the active layer 222, and a positive electrode 227 (also referred to as a second positive electrode) disposed on a side of the reflective layer 223 away from the active layer 222. When the laser 22 is powered, the negative electrode 226 and the positive electrode 227 of the laser 22 receive a voltage or current to form a voltage difference, thereby causing the active layer 222 to generate photons. The projection of the positive electrode 227 on the substrate 225 does not overlap with the projection of the oxidation hole 224 on the substrate 225, and the substrate 225 is a conductive substrate. In some embodiments, the oxidation hole 224 is formed by forming a ring-shaped STI2, and then growing oxide from the inner wall of the ring-shaped STI2 to form the oxidation hole 224 of a predetermined size. The STI2 can be a circular ring, thereby forming a circular oxidation hole, or a polygonal ring, thereby forming a polygonal oxidation hole. In the z-axis direction, the STI2 penetrates the reflective layer 223 and the active layer 222 and contacts the reflective layer 221. Typically, after the STI2 is formed in the laser 22 and the oxidation hole 224 is made, an insulating material is deposited within the STI2 and on the reflective layer 223 to form an insulating layer 228. Then, a pattern of the positive electrode 227 is formed on the insulating layer 228 through photolithography and etching processes, thereby forming the positive electrode 227. The insulating layer 228 exists between the positive electrode 227 and the STI2, and the positive electrode 227 contacts the reflective layer 223. A portion of the insulating layer 228 also exists in the area surrounded by the positive electrode 227. The projection of this portion of the insulating layer 228 on the active layer 222 covers the projection of the oxidation hole 224 on the active layer 222.

[0079] In another embodiment, as shown in FIG8 , the laser 22 further includes a conductive layer 220 (also referred to as a second conductive layer) disposed between the substrate 225 and the reflective layer 221, a negative electrode 226 in contact with the conductive layer 220, and a positive electrode 227 disposed on the side of the reflective layer 223 away from the active layer 222. When the laser 22 is powered, the negative electrode 226 and the positive electrode 227 of the laser 22 receive a voltage or current to form a voltage difference, thereby causing the active layer 222 to generate photons. The projection of the positive electrode 227 on the substrate 225 does not overlap with the projection of the oxide hole 224 on the substrate 225, and the substrate 225 is an insulating substrate. In some embodiments, the oxide hole 224 is formed by forming a ring-shaped shallow trench isolation (STI) STI2, and then growing oxide from the inner wall of the ring-shaped STI2 inward to form the oxide hole 224 of a predetermined size. The STI2 can be a circular ring, thereby making the oxidation hole circular, or the STI2 can be a polygonal ring, thereby making the oxidation hole polygonal. Along the z-axis, the STI2 penetrates the reflective layer 223 and the active layer 222 and contacts the reflective layer 221 (similar to the STI2 shown in (c) of FIG6 ). In some examples, the STI2 also penetrates the reflective layer 221 and contacts the conductive layer 220. Typically, after STI2 is formed in the laser 22 and the oxidation hole 224 is made, an insulating material is deposited inside the STI2 and on the reflective layer 223 to form an insulating layer 228, and then a pattern of the positive electrode 227 is made on the insulating layer 228 by photolithography and etching processes, thereby making the positive electrode 227, wherein an insulating layer 228 exists between the positive electrode 227 and the STI2, the positive electrode 227 is in contact with the reflective layer 223, and there is also a partial insulating layer 228 in the area surrounded by the positive electrode 227, and the projection of this partial insulating layer 228 on the active layer 222 covers the projection of the oxidation hole 224 on the active layer 222.

[0080] For example, as shown in FIG8 , regardless of whether the STI2 penetrates the reflective layer 223 and the active layer 222, or penetrates the reflective layer 223, the active layer 222, and the reflective layer 221, the negative electrode 226 in FIG8 may or may not be in contact with the reflective layer 221. For example, an insulating layer may be provided between the reflective layer 221 and the negative electrode 226 to prevent the negative electrode 226 from contacting the reflective layer 221. Alternatively, a predetermined spacing may be provided between the reflective layer 221 and the negative electrode 226 in the x-axis direction to prevent the negative electrode 226 from contacting the reflective layer 221.

[0081] In the laser array 20, the laser 21 includes a reflective layer 211, an active layer 212 and a reflective layer 213 arranged in sequence along the epitaxial direction. An oxidation hole 214 is provided in the reflective layer 213. When the laser array 20 receives a voltage or current, the voltage or current is transmitted to the laser 21, so that the laser 21 is powered. Therefore, the active layer 212 of the laser 21 generates a first photon, and the first photon oscillates in the resonant cavity formed by the reflective layer 211 and the reflective layer 213, thereby generating a first laser and outputting it through the oxidation hole 214. The laser 22 includes a reflective layer 221, an active layer 222, and a reflective layer 223, which are sequentially arranged along the epitaxial direction. Oxide holes 224 are provided in the reflective layer 223. A light-blocking layer 229 is also provided on the side of the reflective layer 223 away from the active layer 222. The projection of the light-blocking layer 229 on the active layer 222 overlaps with the projection of the oxide holes 224 on the active layer 222. When the laser array 20 receives a voltage or current, the voltage or current can be transmitted to the laser 22, energizing the laser 22. As a result, the active layer 222 of the laser 22 generates a second photon, which oscillates in the resonant cavity formed by the reflective layer 221 and the reflective layer 223, generating a second laser. This second laser is transmitted through the oxide holes 224 to the light-blocking layer 229, which blocks the output of the second laser or partially outputs the second laser. The emitted lasers output by the laser array 20 are specifically the first laser and the second laser. When lasers 21 and 22 are connected in parallel and the laser array 20 receives a constant voltage, the differential resistance of the lasers 21 and 22 connected in parallel is lower than the differential resistance of laser 21. When lasers 21 and 22 are connected in parallel and the laser array 20 receives a constant current, the optical power of the emitted laser light output by the laser array 20 will change. When lasers 21 and 22 are connected in series and the laser array 20 receives a constant voltage, the optical power of the emitted laser light output by the laser array 20 will change. In other words, when the laser array includes laser 22, the differential resistance of the laser array is adjustable, and the optical power of the emitted laser light output is adjustable.

[0082] Exemplarily, as shown in Figures 9, 12, 15, 16 and 19, the laser array 20 includes multiple lasers 21 and at least one laser 22; the multiple lasers 21 are connected in parallel; and at least one laser 21 is electrically connected to any one laser 22.

[0083] Specifically, as shown in FIG9 , the laser array 20 shown in FIG9 includes a plurality of lasers 21 and at least one laser 22; the plurality of lasers 21 are connected in parallel; at least one laser 21 is specifically connected in parallel with any one of the lasers 22, and the plurality of lasers 22 are connected in parallel. Specifically, the plurality of lasers 21 include lasers 21a and lasers 21b, and the plurality of lasers 22 include lasers 22a and lasers 22b, wherein lasers 21a and lasers 21b are connected in parallel, lasers 22a and lasers 22b are connected in parallel, and lasers 21b and lasers 22a are connected in parallel.

[0084] Illustratively, FIG10 is a cross-sectional view along AA′ of FIG9 , wherein the structure of the laser 21 shown in FIG10 is as shown in FIG6( b ), and the structure of the laser 22 shown in FIG10 is as shown in FIG6( c ). Laser 21a is connected in parallel with laser 21b, the positive electrode 217 of laser 21a is connected to the positive electrode 217 of laser 21b, and the negative electrode 216 of laser 21a is connected to the negative electrode 216 of laser 21b; laser 22a is connected in parallel with laser 22b, specifically, the positive electrode 227 of laser 22a is connected to the positive electrode 227 of laser 22b, and the negative electrode 226 of laser 22a is connected to the negative electrode 226 of laser 22b; laser 21b is connected in parallel with laser 22a, specifically, the positive electrode 217 of laser 21b is connected to the positive electrode 227 of laser 22a, and the negative electrode 216 of laser 21b is connected to the negative electrode 226 of laser 22a.

[0085] As shown in FIG10 , when manufacturing the laser array 21 shown in FIG9 , the steps include: a first step: sequentially epitaxially growing a high-refractive-index semiconductor material layer for providing electrons, a semiconductor material layer for high optical gain, and a high-refractive-index semiconductor material layer for providing holes on a substrate; a second step: performing photolithography and etching processes on the high-refractive-index semiconductor material layer for providing holes, and using the high-refractive-index semiconductor material layer for providing electrons as an etching stop layer to manufacture an annular STI1a, an annular STI1b, an annular STI2a, and an annular STI2b, wherein the area surrounded by STI1a is the laser 21a, the area surrounded by STI1b is the laser 21b, the area surrounded by STI2a is the laser 22a, and the area surrounded by STI2b is the laser 22b. Among them, the reflection layer 211 of laser 21a, the reflection layer 211 of laser 21b, the reflection layer 221 of laser 22a, and the reflection layer 221 of laser 22b are specifically high refractive index semiconductor material layers that provide electrons, the active layer 212 of laser 21a, the active layer 212 of laser 21b, the active layer 212 of laser 22a, and the active layer 212 of laser 22b are specifically high optical gain semiconductor material layers, and the reflection layer 213 of laser 21a, the reflection layer 213 of laser 21b, the reflection layer 223 of laser 22a, and the reflection layer 223 of laser 22b are specifically semiconductor material layers that provide holes.

[0086] Step 3: Grow oxide from the inner wall of the STI. Specifically, grow oxide from the inner wall of the annular STI 1a to form the oxide hole 214 of the laser 21a; grow oxide from the inner wall of the annular STI 1b to form the oxide hole 214 of the laser 21b; grow oxide from the inner wall of the annular STI 2a to form the oxide hole 224 of the laser 22a; and grow oxide from the inner wall of the annular STI 2b to form the oxide hole 224 of the laser 22b.

[0087] Step 4: Deposit insulating material into the STI and on the semiconductor material layer providing holes to form insulating layer 218 of laser 21a, insulating layer 218 of laser 21b, insulating layer 228 of laser 22a and insulating layer 228 of laser 22b.

[0088] Step 5: Deposit a conductive material on the high-refractive-index semiconductor material that provides holes to produce the positive electrode 217 of laser 21a, the positive electrode 217 of laser 21b, the positive electrode 227 of laser 22a, and the positive electrode 227 of laser 22b, and all the positive electrodes are connected to the pin PAD1 of the laser array 20; deposit a conductive material on the side of the substrate away from the high-refractive-index semiconductor material that provides holes to produce the negative electrode 216 of laser 21a, the negative electrode 216 of laser 21b, the negative electrode 226 of laser 22a, and the negative electrode 226 of laser 22b, and all the negative electrodes are connected to the pin PAD2 of the laser array 20. For example, FIG9 is a top view of laser array 20. When lasers 21 and 22 in laser array 20 are arranged in the layer structure shown in FIG10 , the negative electrode is at the bottom in the z-axis direction, and the positive electrode is at the top in the z-axis direction. Therefore, in the top view shown in FIG9 , pin PAD1 is generally visible, but pin PAD2 is not, because pin PAD2 is at the bottom. The presence of pin PAD2 is indicated by a dotted box in FIG9 .

[0089] Step 6: A light blocking layer 229 is formed on each laser 22 , and the projection of the light blocking layer 229 on the active layer 222 overlaps with the projection of the oxidation hole 224 on the active layer 222 .

[0090] For example, FIG11 is a cross-sectional view taken along AA' of FIG9, wherein the structure of the laser 21 shown in FIG11 is shown in FIG7, and the structure of the laser 22 shown in FIG11 is shown in FIG8. The laser 21a is connected in parallel with the laser 21b, the positive electrode 217 of the laser 21a is connected to the positive electrode 217 of the laser 21b, the conductive layer 210 of the laser 21a is in contact with the conductive layer 210 of the laser 21b, and the negative electrode 216 of the laser 21a is shared with the negative electrode 216 of the laser 21b; the laser 22a is connected in parallel with the laser 22b, specifically, the positive electrode 227 of the laser 22a is connected to the positive electrode 227 of the laser 22b, and the laser 22a is connected in parallel with the laser 22b. The conductive layer 220 of the laser 21b is in contact with the conductive layer 220 of the laser 22b, and the negative electrode 226 of the laser 22a is shared with the negative electrode 226 of the laser 22b; the laser 21b is connected in parallel with the laser 22a, specifically, the positive electrode 217 of the laser 21b is connected to the positive electrode 227 of the laser 22a, the conductive layer 210 of the laser 21b is in contact with the conductive layer 220 of the laser 22a, and the negative electrode 216 of the laser 21b is shared with the negative electrode 226 of the laser 22a.

[0091] As shown in FIG11 , when manufacturing the laser array 21 shown in FIG9 , the following steps are included: a first step: sequentially growing a conductive semiconductor material layer, a high-refractive-index semiconductor material layer providing electrons, a semiconductor material layer providing high optical gain, and a high-refractive-index semiconductor material layer providing holes on a substrate; a second step is similar to the second step shown in FIG10 , but in FIG11 , the etch stop layer in the second step is a conductive semiconductor material layer, and the conductive layers 210 of laser 21a, 210 of laser 21b, 220 of laser 22a, and 220 of laser 22b are specifically conductive semiconductor material layers. The third step is similar to the third step shown in FIG10 . The fourth step is similar to the fourth step shown in FIG10 .

[0092] Step 5: Depositing a conductive material on the high-refractive-index semiconductor material that provides holes to form the positive electrode 217 of laser 21a, the positive electrode 217 of laser 21b, the positive electrode 227 of laser 22a, and the positive electrode 227 of laser 22b. All of the positive electrodes are connected to pin PAD1 of laser array 20. Depositing a conductive material on the conductive semiconductor material layer to form the negative electrode 216 of laser 21a, the negative electrode 216 of laser 21b, the negative electrode 226 of laser 22a, and the negative electrode 226 of laser 22b. All of the negative electrodes are shared and connected to pin PAD2 of laser array 20. The shared negative electrode may or may not be in contact with the high-refractive-index semiconductor material that provides electrons. FIG11 specifically illustrates the case where the shared negative electrode is not in contact with the high-refractive-index semiconductor material that provides electrons. An insulating layer is provided between the shared negative electrode and the high-refractive-index semiconductor material that provides electrons. For example, FIG9 is a top view of the laser array 20. When the lasers 21 and 22 in the laser array 20 are arranged in the layer structure shown in FIG11, the top view shown in FIG9 shows the pins PAD1 and PAD2.

[0093] Step 6 Refer to step 6 shown in FIG. 10 .

[0094] For example, as shown in FIG10 and FIG11 , when the laser array 20 is grounded through pin PAD2 and receives a fixed voltage or a fixed current through pin PAD1 , the lasers 21 a , 21 b , 22 a and 22 b can operate in parallel.

[0095] For example, the laser array 20 shown in FIG9 specifically includes M lasers 21 and N lasers 22, where M is a positive integer greater than or equal to 2, and N is a positive integer greater than or equal to 1. The differential resistance of the laser 21 and the laser 22 is approximately equal, and is recorded as R s , then in the laser array 20 shown in FIG9 , the differential resistance R of the laser array 20 is R s / (M+N) (Formula 1). It can be seen from Formula 1 that when the number N increases, the differential resistance of the laser array 20 will decrease.

[0096] For example, the laser array 20 may be disposed in the partition A2 of the laser array 11 shown in FIG2 to reduce the differential resistance of the partition A2 of the laser array 11 when emitting laser light. Alternatively, the laser array 20 may be disposed in the partition A3 of the laser array 11 shown in FIG4 to reduce the differential resistance of the partition A3 of the laser array 11 when emitting laser light.

[0097] For example, referring to the laser array 20 shown in FIG12 , the laser array 20 includes one or more regions A4 (also referred to as the first region). FIG12 specifically shows four regions A4, namely, region A4a, region A4b, region A4c, and region A4d. Region A4 includes a laser 22. For example, region A4 may include one laser 22, or may include multiple lasers 22, and the multiple lasers 22 included in region A4 are connected in parallel.

[0098] At least one laser 21 in the laser array 20 is connected in parallel with the laser 22 in the area A4, and the lasers 22 in any two areas A4 are connected in parallel. When the laser array 20 includes multiple areas A4, at least one laser 21 in the laser array 20 is connected in parallel with the laser 22 in each area A4, and the lasers 22 in any two areas A4 are connected in parallel. Therefore, it can be said that each laser 21 in the laser array 20 is connected in parallel with the laser 22 in each area A4.

[0099] The lasers 22 in any two regions A4 are electrically isolated. Specifically, the negative electrodes 216 of the multiple lasers 21 shown in FIG12 are electrically connected to pin PAD2, and the positive electrodes 217 of the multiple lasers 21 are electrically connected to pin PAD1. In FIG12, each region A4 includes two lasers 22 connected in parallel, and the negative electrode 226 of the laser 22 in each region A4 is also electrically connected to pin PAD2, and the positive electrode 227 of the laser 22 in each region A4 is not electrically connected to pin PAD1. The positive electrodes 227 of the lasers 22 in any two regions A4 are not connected. Among them, the positive electrodes 227 of the two lasers 22 in area A4a are electrically connected to pin PAD3 of the laser array 20; the positive electrodes 227 of the two lasers 22 in area A4b are electrically connected to pin PAD4 of the laser array 20; the positive electrodes 227 of the two lasers 22 in area A4c are electrically connected to pin PAD5 of the laser array 20; and the positive electrodes 227 of the two lasers 22 in area A4d are electrically connected to pin PAD6 of the laser array 20.

[0100] For example, in the laser array 20 shown in FIG12 , when the laser array 20 is grounded via pin PAD2 and receives a fixed voltage or a fixed current via pins PAD1 and PAD3, the laser 21 and the laser 22 in region A4a can be operated in parallel, while the lasers 22 in other regions A4 do not operate. In the laser array 20 shown in FIG12 , when the laser array 20 is grounded via pin PAD2 and receives a fixed voltage or a fixed current via pins PAD1, PAD3, and PAD4, the laser 21, the laser 22 in region A4a, and the laser 22 in region A4b can be operated in parallel, while the lasers 22 in other regions A4 do not operate.

[0101] More specifically, referring to FIG. 13 , FIG. 13 is a cross-sectional view of the laser array shown in FIG. 12 along line BB'. Region A4b includes laser 22c, and region A4c includes laser 22d. In FIG. 13 , the region surrounded by STI 2c specifically represents laser 22c, and the region surrounded by STI 2d specifically represents laser 22d. The lasers 22 in any two regions A4 are electrically isolated, i.e., laser 22c is electrically isolated from laser 22d. Specifically, as shown in FIG. 13 , the negative electrode 226 of laser 22c is connected to the negative electrode 226 of laser 22d, but the positive electrode 227 of laser 22c is not connected to the positive electrode 227 of laser 22d, thereby electrically isolating laser 22c from laser 22d.

[0102] The structure of the laser 22 shown in Figure 13 is shown in (c) of Figure 6. In other embodiments, the structure of the laser 22 shown in Figure 13 may be as shown in Figure 8. In this case, the conductive layers 220 of the two lasers 22 are in contact, the negative electrodes 226 of the two lasers 22 are shared, and the positive electrodes 227 of the two lasers 22 are not connected, so that the two lasers 22 are electrically isolated.

[0103] In the laser array 20 shown in FIG12 , the laser array 20 includes one or more regions A4; the region A4 includes a laser 22; at least one laser 21 in the laser array 20 is connected in parallel with the laser 22 in the region A4, and the lasers 22 in any two regions A4 are electrically isolated. The laser array 20 receives a fixed voltage. Assume that the laser array 20 includes M lasers 21 and X regions A4, and one region A4 includes Y lasers 22, where X is a positive integer greater than or equal to 1, and Y is a positive integer greater than or equal to 1. Since at least one laser 21 is connected in parallel with the laser 22 in the region A4, when the laser array 20 receives a fixed voltage and all the lasers are working, the optical power of the lasers output by the multiple lasers 21 does not change. And the differential resistance R of the laser array 20 is Rs / (M+X×Y) (Formula 2), as can be seen from Formula 2, when X increases and / or Y increases, the differential resistance of the laser array 20 will decrease; when X decreases and / or Y decreases, the differential resistance of the laser array 20 will increase.

[0104] When the laser array 20 shown in FIG12 receives a fixed current I0 and all lasers are operating, since multiple lasers 21 are connected in parallel, at least one laser 21 is connected in parallel with the laser 22 in area A4, and multiple lasers 22 are connected in parallel, the current I flowing through the M lasers 21 is I=M×I0 / (M+X×Y) (Formula 3). According to the relationship between power and current, ΔP=ΔI×SE (Formula 4), where SE is the slope efficiency, ΔI is the change in the current flowing through the M lasers 21, and ΔP is the change in the optical power output by the M lasers 21 in parallel. According to Formula 3 and Formula 4, when X increases and / or Y increases, the current I flowing through the M lasers 21 decreases, and the optical power of the lasers output by the M lasers 21 in the laser array 20 will decrease; when X decreases and / or Y decreases, the current I flowing through the M lasers 21 increases, and the optical power of the lasers output by the M lasers 21 in the laser array 20 will increase.

[0105] Exemplarily, in the laser array 20 shown in FIG12 , the laser array 20 further includes an area A5, wherein the area A5 includes a plurality of lasers 21, the plurality of lasers 21 are connected in parallel, and the lasers 21 in the area A5 are electrically isolated from the lasers 22 in any one of the areas A4.

[0106] For example, referring to FIG14 , FIG14 is a cross-sectional view taken along CC′ of FIG12 , in which region A5 includes laser 21c and region A4d includes laser 22e. In FIG14 , the region surrounded by STI1c is specifically laser 21c, and the region surrounded by STI2e is specifically laser 22e. As shown in FIG11 , although the negative electrode 216 of laser 21c is connected to the negative electrode 226 of laser 22e, the positive electrode 217 of laser 21c is not connected to the positive electrode 227 of laser 22e, thereby electrically isolating laser 21c from laser 22e. Similarly, when the positive electrode 217 of any laser 21 in region A5 is not connected to the positive electrode 227 of any laser 22 in region A4, the laser 21 in region A5 is electrically isolated from the laser 22 in any region A4. Among them, the negative electrodes 216 of multiple lasers 21 in area A5 are electrically connected to the pin PAD2 of the laser array 20, the positive electrodes 217 of multiple lasers 21 in area A5 are electrically connected to the pin PAD1 of the laser array 20, and the positive electrode 227 of any laser 22 in any area A4 is not electrically connected to the pin PAD1 of the laser array 20.

[0107] The structure of the laser 21 shown in FIG14 is shown in FIG6(b), and the structure of the laser 22 shown in FIG14 is shown in FIG6(c). In other embodiments, the structure of the laser 21 shown in FIG14 may be shown in FIG7, and the structure of the laser 22 shown in FIG14 may be shown in FIG8. In this case, the conductive layer 210 of the laser 21 is in contact with the conductive layer 220 of the laser 22, the negative electrode 216 of the laser 21 is shared with the negative electrode 226 of the laser 22, and the positive electrode 217 of the laser 21 is not connected to the positive electrode 227 of the laser 22, so that the two lasers 22 are electrically isolated.

[0108] In other embodiments, referring to FIG. 15 , compared to the laser array 20 shown in FIG. 12 , region A5 in the laser array 20 shown in FIG. 15 further includes one or more lasers 22 , and the lasers 21 and 22 in region A5 are connected in parallel.

[0109] In the laser array 20 shown in FIG15 , it is assumed that the laser array 20 includes X areas A4, each area A4 includes Y lasers 22, and the laser array 20 further includes area A5, which includes M lasers 21 and N lasers 22. The differential resistance of the laser 21 and the laser 22 are approximately equal, and are denoted as R. s .

[0110] When the laser array 20 shown in FIG15 receives a fixed voltage and all lasers are working, since at least one laser 21 is connected in parallel with the laser 22 in area A4, the optical power of the lasers output by the plurality of lasers 21 does not change. And the differential resistance R of the laser array 20 is R s / (M+N+X×Y) (Formula 5), ​​as can be seen from Formula 5, when X increases and / or Y increases, the differential resistance of the laser array 20 will decrease; when X decreases and / or Y decreases, the differential resistance of the laser array 20 will increase.

[0111] When the laser array 20 shown in FIG15 receives a fixed current I0, since the lasers 21 and 22 in region A5 are connected in parallel, at least one laser 21 in region A5 is connected in parallel with the laser 22 in region A4, and multiple lasers 22 are connected in parallel, the current I flowing through the M lasers 21 is calculated as follows: (M+N)×I0 / (M+N+X×Y) (Formula 6). According to Formula 6 and the above Formula 4, when X increases and / or Y increases, the current I flowing through the M lasers 21 decreases, and the optical power of the emitted laser light output by the M lasers 21 in the laser array 20 will decrease; when X decreases and / or Y decreases, the current I flowing through the M lasers 21 increases, and the optical power of the emitted laser light output by the M lasers 21 in the laser array 20 will increase.

[0112] In other embodiments, referring to the laser array 20 shown in FIG. 16 , the laser array 20 includes one or more regions A4. FIG. 16 specifically shows four regions A4, namely, region A4a, region A4b, region A4c, and region A4d. Region A4 includes a laser 22. For example, region A4 may include one laser 22, or may include multiple lasers 22, with the multiple lasers 22 in region A4 being connected in parallel.

[0113] At least one laser 21 in the laser array 20 is connected in series with the laser 22 in area A4; the lasers 22 in any two areas A4 are electrically isolated, and the lasers 22 in any two areas A4 are connected in parallel. Specifically, as shown in FIG16 , the negative electrodes 216 of the plurality of lasers 21 are electrically connected to the pin PAD2, and the positive electrodes 217 of the plurality of lasers 21 are electrically connected to the pin PAD1. In FIG16 , each area A4 includes two lasers 22 connected in parallel, and the positive electrode 227 of the laser 22 in each area A4 is also electrically connected to the pin PAD2 (as shown in the gray box in FIG16 ), the negative electrode 226 of the laser 22 in each area A4 is not electrically connected to the pin PAD1 or PAD2, and the negative electrodes 226 of the lasers 22 in any two areas A4 are not connected. Among them, the negative electrodes 226 of the two lasers 22 in area A4a are electrically connected to pin PAD3 of the laser array 20; the negative electrodes 226 of the two lasers 22 in area A4b are electrically connected to pin PAD4 of the laser array 20; the negative electrodes 226 of the two lasers 22 in area A4c are electrically connected to pin PAD5 of the laser array 20; and the negative electrodes 226 of the two lasers 22 in area A4d are electrically connected to pin PAD6 of the laser array 20.

[0114] For example, in the laser array 20 shown in FIG16 , when the laser array 20 receives a fixed voltage or a fixed current through pin PAD1 and is grounded through pin PAD3, the lasers 21 can be operated in parallel, the lasers 22 in area A4a can be operated in parallel, and the parallel lasers 21 and the parallel lasers 22 can be operated in series, while the lasers 22 in other areas A4 do not operate. In the laser array 20 shown in FIG16 , when the laser array 20 receives a fixed voltage or a fixed current through pin PAD1 and is grounded through pins PAD3 and PAD4, the lasers 21 can be operated in parallel, the lasers 22 in area A4a can be operated in parallel with the lasers 22 in area A4a, and the parallel lasers 21 and the parallel lasers 22 can be operated in series, while the lasers 22 in other areas do not operate.

[0115] More specifically, referring to FIG17 , FIG17 is a cross-sectional view of the laser array 20 shown in FIG16 along section DD′. Region A4d includes lasers 22f and 22g, and the laser array 20 further includes lasers 21d and 21e. In FIG17 , the area surrounded by STI1d is specifically laser 21d, the area surrounded by STI1e is specifically laser 21e, the area surrounded by STI2f is specifically laser 22f, and the area surrounded by STI2g is specifically laser 22g. Lasers 21d and 21e are connected in parallel, with the positive electrode 217 of laser 21d connected to the positive electrode 217 of laser 21e, the conductive layer 210 of laser 21d in contact with the conductive layer 210 of laser 21e, and the negative electrode 216 of laser 21d shared with the negative electrode 216 of laser 21e. Laser 22f is connected in parallel with laser 22g. Specifically, the positive electrode 227 of laser 22f is connected to the positive electrode 227 of laser 22g, the conductive layer 220 of laser 22f is in contact with the conductive layer 220 of laser 22g, and the negative electrode 226 of laser 22f is shared with the negative electrode 226 of laser 22g. Laser 21 is connected in series with laser 22 in area A4d. Specifically, the negative electrode 216 of laser 21e is electrically connected to the positive electrode 227 of laser 22f, and the conductive layer 210 of laser 21e is not in contact with the conductive layer 220 of laser 22f.

[0116] For example, when the laser 22f and the laser 22g shown in FIG. 17 are replaced with the laser 22 in the area A4a, area A4b, or area A4c, the cross-sectional view along the direction parallel to the x-axis is similar to that in FIG. 17 .

[0117] More specifically, referring to FIG18 , FIG18 is a cross-sectional view of the laser array 20 shown in FIG16 along line EE′. Region A4b includes laser 22h, and region A4c includes laser 22k. In FIG18 , the region surrounded by STI 2h is specifically laser 22h, and the region surrounded by STI 2k is specifically laser 22k. Among them, any two lasers 22 in area A4 are electrically isolated, that is, laser 22h is electrically isolated from laser 22k. Specifically, as shown in FIG18 , the conductive layer 220 of laser 22h is not in contact with the conductive layer 220 of laser 22k, and there is an insulating portion between the conductive layer 220 of laser 22h and the conductive layer 220 of laser 22k. In addition, the negative electrode 226 of laser 22h in FIG18 is not connected to the negative electrode 226 of laser 22k, the negative electrode 226 of laser 22h is not connected to the positive electrode 227 of laser 22k, and the positive electrode 227 of laser 22h is not in contact with the positive electrode 227 of laser 22k, thereby electrically isolating laser 22h from laser 22k. The positive electrode 227 of laser 22h and the positive electrode 227 of laser 22k are connected to pin PAD2, thereby connecting laser 21 in series with laser 22 in area A4d.

[0118] In the laser array 20 shown in FIG16 , the laser array 20 includes one or more regions A4; each region A4 includes a laser 22; at least one laser 21 in the laser array 20 is connected in series with a laser 22 in region A4, any two lasers 22 in regions A4 are electrically isolated, and any two lasers 22 in regions A4 are connected in parallel. Assume that the laser array 20 includes M lasers 21 and X regions A4, and one region A4 includes Y lasers 22. The differential resistance of the laser 21 and the laser 22 is approximately equal, denoted as R. s , and the laser array 20 receives a fixed current, and when all lasers are working, since the laser 21 is connected in series with the laser 22 in area A4, multiple lasers 21 are connected in parallel, and any two lasers 22 in area A4 are connected in parallel, the optical power of the laser output by the laser 21 does not change, and the differential resistance R of the laser array 20 is R s / M+R s / (X×Y) (Formula 7), as can be seen from Formula 7, when X increases and / or Y increases, the differential resistance of the laser array 20 will decrease; when X decreases and / or Y decreases, the differential resistance of the laser array 20 will increase.

[0119] When the laser array 20 shown in FIG16 receives a fixed voltage V0 and all lasers are operating, since the laser 21 is connected in series with the laser 22 in region A4, multiple lasers 21 are connected in parallel, and any two lasers 22 in region A4 are connected in parallel, the voltage V distributed to the M lasers 21 is = (X×Y)×V0 / (M+X×Y) (Formula 8). According to the relationship between voltage and current, ΔV = ΔI*R s / M (Formula 9), where ΔV is the change in voltage distributed to the multiple parallel lasers 21, and ΔI is the change in current flowing through the M lasers 21. According to Formula 9 and Formula 4, dividing the left and right sides of the equal sign respectively yields ΔP = ΔV × SE × M / R s (Formula 10). According to Formula 10, when X increases and / or Y increases, the optical power of the emitted laser light output by the M lasers 21 in the laser array 20 will increase; when X decreases and / or Y decreases, the optical power of the emitted laser light output by the M lasers 21 in the laser array 20 will decrease.

[0120] For example, the laser array 20 shown in FIG16 further includes an area A5, wherein the area A5 includes a plurality of lasers 21, the plurality of lasers 21 being connected in parallel, and the lasers 21 in the area A5 being electrically isolated from the lasers 22 in any one of the areas A4. When the laser array 20 receives a fixed voltage or a fixed current through pin PAD1 and is grounded through pin PAD2, the lasers 21 can operate in parallel, and all the lasers 22 are inoperative.

[0121] In other embodiments, as shown in FIG19 , compared with the laser array 20 shown in FIG16 , the area A5 in the laser array 20 shown in FIG19 further includes one or more lasers 22 , and the lasers 21 and lasers 22 in the area A5 are connected in parallel.

[0122] In the laser array 20 shown in FIG19 , the laser array 20 includes one or more regions A4; region A4 includes lasers 22; at least one laser 21 in the laser array 20 is connected in series with the laser 22 in region A4, any two lasers 22 in regions A4 are electrically isolated, and any two lasers 22 in regions A4 are connected in parallel; the laser array 20 also includes region A5, region A5 includes multiple lasers 21 and one or more lasers 22, and the lasers 21 and lasers 22 in region A5 are connected in parallel. Assume that the laser array 20 includes X regions A4, one region A4 includes Y lasers 22, and region A5 includes M lasers 21 and N lasers 22. The differential resistance of the laser 21 and the laser 22 is approximately equal, which is recorded as R s .

[0123] When the laser array 20 shown in FIG19 receives a fixed current and all lasers are working, since the laser 21 is connected in series with the laser 22 in the region A4, multiple lasers 21 are connected in parallel, and any two lasers 22 in the region A4 are connected in parallel, the optical power of the laser output by the laser 21 does not change, and the differential resistance R of the laser array 20 is R s / (M+N)+R s / (X×Y) (Formula 11), as can be seen from Formula 11, when X increases and / or Y increases, the differential resistance of the laser array 20 will decrease; when X decreases and / or Y decreases, the differential resistance of the laser array 20 will increase.

[0124] When the laser array 20 shown in FIG19 receives a fixed voltage V0 and all lasers are operating, since the laser 21 is connected in series with the laser 22 in area A4, multiple lasers 21 are connected in parallel, and any two lasers 22 in area A4 are connected in parallel, the voltage V distributed to the M lasers 21 is V = (X × Y) × V0 / (M + N + X × Y) (Formula 12). According to the relationship between voltage and current, it can be seen that ΔV = ΔI * R s / (M+N) (Formula 13), where ΔV is the change in voltage distributed to the multiple parallel lasers 21, and ΔI is the change in current flowing through the M lasers 21. According to Formula 13 and Formula 4, dividing the left and right sides of the equal sign respectively yields ΔP = ΔV × SE × (M+N) / R s (Formula 14). According to Formula 14, when X increases and / or Y increases, the optical power of the emitted laser light output by the M lasers 21 in the laser array 20 will increase; when X decreases and / or Y decreases, the optical power of the emitted laser light output by the M lasers 21 in the laser array 20 will decrease.

[0125] For example, in the laser array 20 shown in Figures 9, 12, 15, 16, and 19, it is assumed that the laser 22 does not output laser light when in operation, so the optical power of the emitted laser output by the laser array 20 is the optical power of the laser output by the laser 21 in the laser array 20.

[0126] For example, the laser array 20 shown in Figures 9, 12, 15, 16, and 19 can be set in the laser radar 10 shown in Figure 1, and the driving device 12 is used to input a fixed voltage or a fixed current to the laser array 20 shown in Figures 9, 12, 15, 16, and 19.

[0127] Exemplarily, when the driving device 12 inputs a fixed voltage to the laser array 20 shown in FIG. 9 , the number of lasers 22 in the laser array 20 is negatively correlated with the differential resistance of the laser array 20 .

[0128] Exemplarily, the laser array 20 shown in Figure 12 or Figure 15 or Figure 16 or Figure 19 includes one or more areas A4; the driving device 12 can input a fixed voltage or a fixed current to n areas A4 so that the lasers 22 in the n areas A4 work together with the laser 21, where n is a positive integer greater than or equal to 0.

[0129] For example, when the driving device 12 inputs a fixed voltage to the laser array 20 shown in FIG12 or FIG15 , it is assumed that the driving device 12 can input a fixed voltage to n areas A4, and n is negatively correlated with the differential resistance of the laser array 20. When the driving device 12 inputs a fixed current to the laser array 20 shown in FIG12 or FIG15 , it is assumed that the driving device 12 can input a fixed voltage to n areas A4, and n is negatively correlated with the optical power output by the laser 21 in the laser array 20.

[0130] For example, when the driving device 12 inputs a fixed current to the laser array 20 shown in FIG16 or FIG19 , it is assumed that the driving device 12 can input a fixed voltage to n areas A4, and n is negatively correlated with the differential resistance of the laser array 20. When the driving device 12 inputs a fixed voltage to the laser array 20 shown in FIG16 or FIG19 , it is assumed that the driving device 12 can input a fixed voltage to n areas A4, and n is positively correlated with the optical power output by the laser 21 in the laser array 20.

[0131] In some examples, the driving device 12 is configured to receive an input signal and control the input of a fixed voltage or a fixed current to the n areas A4 based on the input signal. The input signal is the input signal received by the lidar 10. For example, the lidar designer may determine to select n areas A4 for operation based on the parameters of the lidar 10 and the distance between the obstacle and the lidar 10. The lidar 10 then receives the input signal input by the designer, where the input signal indicates the number n of areas A4 selected. The input signal is transmitted to the driving device 12, which in turn causes the driving device 12 to input a fixed voltage or a fixed current to the n areas A4 based on the input signal.

[0132] In other examples, the driving device 12 is configured to receive a feedback signal and, based on the feedback signal, control the input of a fixed voltage or current to the n areas A4. For example, the receiving device 14 is configured to receive reflected laser light, generate a received signal, and transmit the received signal to the signal processing device 13. The reflected laser light is formed when the transmitted laser light encounters an obstacle and is reflected. The signal processing device 13 is configured to generate a feedback signal based on the received signal, the feedback signal indicating the number n of selected areas A4. Exemplarily, when n is positively correlated with the optical power output by the laser 21 in the laser array 20 and the received signal is greater than a predetermined value, i.e., the optical power of the received reflected signal is too high, the feedback signal generated by the signal processing device 13 indicates a decrease in the number n of selected areas A4. Exemplarily, when n is negatively correlated with the optical power output by the laser 21 in the laser array 20 and the received signal is greater than a predetermined value, i.e., the optical power of the received reflected signal is too high, the feedback signal generated by the signal processing device 13 indicates an increase in the number n of selected areas A4.

[0133] Although the present application has been described with reference to specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely illustrative of the present application as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, the present application is intended to include such modifications and variations as fall within the scope of the claims of the present application and their equivalents.

Claims

1. A laser array, characterized in that, The laser array includes a first laser and a second laser; The first laser includes a first reflective layer, a first active layer, and a second reflective layer sequentially arranged along the epitaxial direction. A first oxidation hole is provided in the second reflective layer; The second laser includes a third reflective layer, a second active layer, and a fourth reflective layer sequentially arranged along the epitaxial direction. A second oxidation hole is provided in the fourth reflective layer. A light blocking layer is further provided on a side of the fourth reflective layer away from the second active layer. A projection of the light blocking layer on the second active layer overlaps a projection of the second oxidation hole on the second active layer; The first laser is electrically connected to the second laser.

2. The laser array according to claim 1, wherein The laser array includes a plurality of the first lasers and at least one of the second lasers; The plurality of the first lasers are connected in parallel; At least one of the first lasers is electrically connected to any one of the second lasers.

3. The laser array according to claim 2, wherein The laser array includes one or more first regions; The second laser is included in the first region; At least one of the first lasers is connected in parallel with the second laser in the first region; The second lasers in any two of the first regions are electrically isolated, and the second lasers in any two of the first regions are connected in parallel.

4. The laser array according to claim 2, characterized in that, The laser array includes one or more first regions; The second laser is included in the first region; At least one of the first lasers is connected in series with the second laser in the first region; The second lasers in any two of the first regions are electrically isolated, and the second lasers in any two of the first regions are connected in parallel.

5. The laser array according to claim 3 or 4, characterized in that, The laser array further includes a second region; The second region includes a plurality of the first lasers; The first lasers in the second region are electrically isolated from the second laser in any one of the first regions.

6. The laser array according to claim 5, wherein One or more of the second lasers are further provided in the second region, and the first lasers and the second lasers in the second region are connected in parallel.

7. The laser array according to any one of claims 3-6, wherein A plurality of the second lasers are included in the first region, and the plurality of the second lasers are connected in parallel.

8. The laser array according to any one of claims 1-7, wherein The laser array is configured to receive a fixed voltage.

9. The laser array according to any one of claims 1-7, wherein The laser array is configured to receive a fixed current.

10. The laser array according to any one of claims 1-9, wherein The first laser further includes a first substrate provided on a side of the first reflective layer away from the first active layer, a first negative electrode provided on a side of the first substrate away from the first active layer, and a first positive electrode provided on a side of the second reflective layer away from the first active layer; Alternatively, the first laser further includes a first substrate disposed on a side of the first reflective layer away from the first active layer, a first conductive layer disposed between the first substrate and the first reflective layer, a first negative electrode in contact with the first conductive layer, and a first positive electrode disposed on a side of the second reflective layer away from the first active layer.

11. The laser array according to any one of claims 1-10, wherein the second laser further includes a second substrate disposed on a side of the third reflective layer away from the second active layer, a second negative electrode disposed on a side of the second substrate away from the second active layer, and a second positive electrode disposed on a side of the fourth reflective layer away from the second active layer; Alternatively, the second laser further includes a second substrate disposed on a side of the third reflective layer away from the second active layer, a second conductive layer disposed between the second substrate and the third reflective layer, a second negative electrode in contact with the second conductive layer, and a second positive electrode disposed on a side of the fourth reflective layer away from the second active layer.

12. A lidar, characterized in that, including a driving device and the laser array according to any one of claims 1-11; the driving device is configured to input a fixed voltage or a fixed current to the laser array.

13. The lidar according to claim 12, wherein the laser array includes one or more first regions; the driving device is configured to receive an input signal, and control the input of a fixed voltage or a fixed current to n of the first regions according to the input signal, where the input signal is the input signal received by the lidar, and n is an integer greater than or equal to 0.

14. The lidar according to claim 12, wherein the laser array includes one or more first regions; the driving device is configured to receive a feedback signal, and control the input of a fixed voltage or a fixed current to n of the first regions according to the feedback signal, where n is an integer greater than or equal to 0.

15. The lidar according to claim 14, wherein the lidar further includes a receiving device and a signal processing device; the receiving device is configured to receive the reflected laser, generate a received signal, and transmit the received signal to the signal processing device; the transmitted laser forms the reflected laser after encountering an obstacle; the signal processing device is configured to generate the feedback signal according to the received signal.

16. The lidar according to claim 15, wherein the signal processing device is further configured to determine the distance between the obstacle and the lidar according to the received signal.

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