Vertical Cavity Surface Emitting Laser and Preparation Method Thereof, Lidar System and Light Source Thereof

Abstract

The present invention relates to the technical field of vertical cavity surface emitting lasers, and provides a vertical cavity surface emitting laser and a preparation method thereof, a lidar system and a light source thereof. The vertical cavity surface emitting laser includes a device substrate, the device substrate has a light emitting unit region, the light emitting unit region includes at least two light emitting regions arranged from a self-set position away from the set position, and at least one light emitting unit is provided in each of the light emitting regions; each light emitting unit includes a light emitting hole and a current injection structure arranged around the light emitting hole; the resistance value of the current injection structure corresponding to the light emitting unit in the light emitting region relatively close to the set position is less than the resistance value of the current injection structure corresponding to the light emitting unit in the light emitting region relatively far from the set position, avoiding the phenomenon that the outer light emitting holes prematurely appear high-order modes due to uneven injection current, improving the problem of far-field divergence angle, and ensuring the service performance of the vertical cavity surface emitting laser.

Description

Technical Field

[0001] The present invention belongs to the technical field of vertical cavity surface emitting lasers, and particularly relates to a vertical cavity surface emitting laser and a preparation method thereof, a lidar system and a light source thereof. Background Art

[0002] In the design of vertical cavity surface emitting lasers, the far-field divergence angle and optical power restrict each other, and both of these two indicators are very important for VCSELs. Usually, in order to pursue a small divergence angle, the vertical cavity surface emitting laser reduces the far-field divergence angle at the cost of sacrificing power. Conversely, in order to compensate for the loss of optical power of the vertical cavity surface emitting laser, it is necessary to increase the number of light-emitting holes on the vertical cavity surface emitting laser. The increased light-emitting holes will bring problems such as an increase in chip size and heat generation, and will also cause the phenomenon of uneven injection current, thereby increasing the loss of unit optical power of the light-emitting holes. Moreover, the uneven current injection leads to an increase in the far-field divergence angle, affecting the performance of the vertical cavity surface emitting laser. Summary of the Invention

[0003] An object of the present invention is to at least overcome one of the above-mentioned deficiencies of the prior art, and provide a vertical cavity surface emitting laser and a preparation method thereof, a lidar system and a light source thereof, so as to avoid an excessive far-field divergence angle of the vertical cavity surface emitting laser and ensure the performance of the vertical cavity surface emitting laser.

[0004] The technical solution of the present invention is: a vertical cavity surface emitting laser, including a device substrate, the device substrate having a light-emitting unit area, the light-emitting unit area being provided with at least two light-emitting regions arranged from a self-set position away from the set position, each of the light-emitting units being disposed in each of the light-emitting regions, and at least one light-emitting unit being provided in each of the light-emitting regions;

[0005] Each of the light-emitting units includes a light-emitting hole and a current injection structure disposed around the light-emitting hole; the resistance value of the current injection structure corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is less than the resistance value of the current injection structure corresponding to the light-emitting unit in the light-emitting region relatively far from the set position;

[0006] The set position is the center point of the light-emitting unit area, or the device substrate is provided with a first power supply access portion on one side of the light-emitting unit area, and the set position is a position away from the first power supply access portion.

[0007] Optionally, the light-emitting region includes a first light-emitting region and a second light-emitting region, the first light-emitting region is closer to the center of the light-emitting unit area than the second light-emitting region, the second light-emitting region is provided on the outer periphery of the first light-emitting region, or the second light-emitting region is provided on a side of the first light-emitting region away from the set position;

[0008] The total resistance value of the current injection structure around each light-emitting unit in the first light-emitting region is R1, the total resistance value of the current injection structure around each light-emitting unit in the second light-emitting region is R2, and R1 is less than R2.

[0009] Optionally, one light-emitting unit is arranged in the first light-emitting region, and the light-emitting unit is arranged at the center point. Alternatively, a plurality of light-emitting units are arranged in the first light-emitting region, and each of the light-emitting units is evenly distributed along the circumferential direction with the center point as the center;

[0010] A plurality of light-emitting units are arranged in the second light-emitting region, and each of the light-emitting units is evenly distributed along the circumferential direction with the center point as the center.

[0011] Optionally, the light-emitting region further includes a third light-emitting region, a plurality of light-emitting units are arranged in the third light-emitting region, and each of the light-emitting units is evenly distributed along the circumferential direction with the center point as the center on the periphery of the second light-emitting region.

[0012] Optionally, a first electrode is arranged on one side of the device substrate, a second electrode is arranged on the other side of the device substrate, the current injection structure includes a conductive channel arranged between the first electrode and the second electrode, and a plurality of the conductive channels are arranged around each of the light-emitting holes;

[0013] The vertical cavity surface emitting laser includes a contact electrode layer; one end of the conductive channel is connected to the first electrode, and the contact electrode layer is a P-type ohmic contact layer connected to the other end of the conductive channel, or the contact electrode layer is an N-type ohmic contact layer arranged closer to the second electrode relative to the conductive channel.

[0014] Optionally, the cross-sectional area of the conductive channel corresponding to the light-emitting unit in the light-emitting region relatively closer to the set position is larger than the cross-sectional area of the conductive channel corresponding to the light-emitting unit in the light-emitting region relatively farther from the set position;

[0015] Or, the number of the conductive channels corresponding to the light-emitting unit in the light-emitting region relatively closer to the set position is larger than the number of the conductive channels corresponding to the light-emitting unit in the light-emitting region relatively farther from the set position;

[0016] Or, the conductivity of the conductive channel corresponding to the light-emitting unit in the light-emitting region relatively closer to the set position is less than the conductivity of the conductive channel corresponding to the light-emitting unit in the light-emitting region relatively farther from the set position;

[0017] Alternatively, the distance between the conductive channel corresponding to the light-emitting unit and the light-emitting hole in the light-emitting region relatively close to the set position is smaller than the distance between the conductive channel corresponding to the light-emitting unit and the light-emitting hole in the light-emitting region relatively far from the set position.

[0018] Optionally, the resistance value of the first electrode corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is smaller than the resistance value of the first electrode corresponding to the light-emitting unit in the light-emitting region relatively far from the set position;

[0019] Alternatively, the resistance value of the contact electrode layer corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is smaller than the resistance value of the contact electrode layer corresponding to the light-emitting unit in the light-emitting region relatively far from the set position.

[0020] Optionally, the width of the contact electrode layer or the first electrode corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is greater than the width of the contact electrode layer corresponding to the light-emitting unit in the light-emitting region relatively far from the set position;

[0021] Or / and, the thickness of the contact electrode layer or the first electrode corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is greater than the thickness of the contact electrode layer in the light-emitting region relatively far from the set position.

[0022] Optionally, the device substrate includes a passivation layer, the conductive channel penetrates through the passivation layer, the first electrode is disposed on one side of the passivation layer and connected to the first end of the conductive channel,

[0023] the contact electrode layer is a P-type ohmic contact layer and is disposed on the other side of the passivation layer and connected to the second end of the conductive channel;

[0024] A semiconductor contact layer and an epitaxial layer are sequentially disposed below the contact electrode layer;

[0025] The epitaxial layer includes a P-DBR layer, a photoelectric confinement layer, a multi-quantum well layer, and an N-DBR layer sequentially arranged from top to bottom.

[0026] The present invention also provides a method for manufacturing a vertical cavity surface emitting laser for manufacturing the above-mentioned vertical cavity surface emitting laser, including:

[0027] When manufacturing the current injection structure of the vertical cavity surface emitting laser, controlling the resistance value of the current injection structure at the set position to be smaller than the resistance value of the current injection structure far from the set position;

[0028] Wherein, the set position is the center point of the light emitting unit area, or, the device substrate is provided with a first power access part located on one side of the light emitting unit area, and the set position is a position far from the first power access part.

[0029] The present invention also provides a light source for a lidar system, including at least one of the above vertical cavity surface emitting lasers.

[0030] The present invention also provides a lidar system, including a transmitting component for transmitting a light source and a receiving component for receiving the light source, and the transmitting component uses the above light source for a lidar system.

[0031] A vertical cavity surface emitting laser, a preparation method thereof, a lidar system and a light source thereof provided by the present invention can deliberately reduce the resistance value of the current injection structure corresponding to the light emitting holes in the central part of the light emitting area, so as to deliberately reduce the resistance value corresponding to the light emitting unit at the central position, which can make the current concentrate relatively towards the central part of the light emitting area, so as to achieve the purpose of adjusting the current injection uniformity of different light emitting units at different positions, and further avoid the phenomenon that the high-order modes appear prematurely in the peripheral light emitting holes due to uneven injection current. The light emitting unit with a relatively small resistance value can carry a higher current and power, while the light emitting unit with a relatively large resistance value carries a relatively low current and power, avoiding the excessive emission angle of the light emitting unit in the edge area from affecting the far-field divergence angle of the vertical cavity surface emitting laser. Moreover, the light emitting unit with a relatively small resistance value has a relatively longer path from the first power access part, and the light emitting unit with a relatively large resistance value has a relatively shorter path from the first power access part. Through resistance complementarity, it is also beneficial to make the injected current uniform. The problem of the far-field divergence angle can be improved by changing the resistance value of the light emitting unit to adjust the current and power, and the far-field divergence angle can be reduced without sacrificing power, ensuring the use performance of the vertical cavity surface emitting laser. Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is a top view of a vertical cavity surface emitting laser provided by an embodiment of the present invention;

[0034] Figure 2 It is a first arrangement diagram of light emitting units in the light emitting unit area of a vertical cavity surface emitting laser provided by an embodiment of the present invention;

[0035] Figure 3It is the second layout schematic diagram of the light-emitting units in the light-emitting unit area of a vertical cavity surface-emitting laser provided by an embodiment of the present invention;

[0036] Figure 4 It is the third layout schematic diagram of the light-emitting units in the light-emitting unit area of a vertical cavity surface-emitting laser provided by an embodiment of the present invention;

[0037] Figure 5 is Figure 1 the schematic cross-sectional view of the A-A cross-section in

[0038] Explanation of reference numerals:

[0039] 100, device substrate; 101, light-emitting unit area; 110, light-emitting unit; 111, light-emitting hole; 210, first power supply access part; 110a, first light-emitting area; 110b, second light-emitting area; 120, first electrode; 112, conductive channel; 130, passivation layer; 140, contact electrode layer; 150, semiconductor contact layer; 160, epitaxial layer; 161, P-DBR layer; 162, optical confinement layer; 163, multiple quantum well layer; 164, N-DBR layer; 170, second electrode. Detailed implementation manners

[0040] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] It should be noted that the terms "arrange" and "connect" should be understood in a broad sense. For example, it can be directly arranged and connected, or indirectly arranged and connected through intermediate components and intermediate structures.

[0042] In addition, in the embodiments of the present invention, if there are terms indicating orientation or positional relationships such as "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., they are based on the orientation or positional relationships shown in the drawings or the conventional placement states or usage states. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the structures, features, devices or elements referred to must have specific orientation or positional relationships, nor must they be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0043] The various specific technical features and embodiments described in the specific implementation methods can be combined in any suitable manner unless there is any contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features / embodiments in the present invention will not be described separately.

[0044] like Figure 1 and Figure 2 As shown, a vertical cavity surface emitting laser provided by an embodiment of the present invention includes a device substrate 100, wherein the device substrate 100 has a light-emitting unit area 101, and the light-emitting unit area 101 includes at least two light-emitting areas, and each light-emitting area is arranged from a set position to away from the set position.

[0045] At least one light-emitting unit 110 is provided in each of the light-emitting regions; each of the light-emitting units 110 includes a light-emitting hole 111 and a current injection structure, and the current injection structure can be provided around the light-emitting hole 111; the resistance value of the current injection structure corresponding to the light-emitting unit 110 in the light-emitting region relatively close to the set position is smaller than the resistance value of the current injection structure corresponding to the light-emitting unit 110 in the light-emitting region relatively far from the set position. The set position can be the center point of the light-emitting unit region 101 (e.g., Figure 2 Alternatively, the device substrate 100 is provided with a first power supply connection portion 210 (which can be used to connect to the positive power supply) located on one side of the light-emitting unit region 101. The predetermined position is a position away from the first power supply connection portion 210, i.e., away from the center of the light-emitting unit region 101 or away from the first power supply connection portion 210. The corresponding resistance value of the light-emitting unit 110 is relatively small. Each light-emitting aperture 111 and the corresponding current injection structure can be considered as a resistor connected in parallel between the positive and negative power supply electrodes.

[0046] The light-emitting unit 110 with a relatively small resistance value can carry a higher current and power, while the light-emitting unit 110 with a relatively large resistance value can carry a relatively low current and power, avoiding the problem that the light-emitting angle of the light-emitting unit 110 in the edge area is too large and affecting the far-field divergence angle of the vertical-cavity surface-emitting laser. Moreover, the light-emitting unit 110 with a relatively small resistance value is relatively farther from the first power supply access part 210, and the light-emitting unit 110 with a relatively large resistance value is relatively closer to the first power supply access part 210. By complementary resistance values, it is also beneficial to make the injected current uniform. In this way, for the light-emitting unit 110 near the set position, the resistance value of its corresponding current injection structure is relatively small, and for the light-emitting unit 110 far from the set position, the resistance value of its corresponding current injection structure is relatively large, making the current tend to flow to the light-emitting unit 110 at the set position. In this embodiment, the set position takes the center of the light-emitting unit area 101 as an example. In this way, the current relatively tends to flow to the light-emitting unit 110 in the central area, making the current and power carried by the light-emitting unit 110 in the central area relatively large, and the current and power carried by the light-emitting unit 110 in the peripheral area relatively small, thereby limiting the increase of the far-field divergence angle. The problem of the far-field divergence angle can be improved by changing the resistance value to adjust the current and power, and it is possible to improve the far-field divergence angle without sacrificing power, ensuring the use performance of the vertical-cavity surface-emitting laser.

[0047] Specifically, as Figures 1 to 3 shown, the light-emitting area includes a first light-emitting area 110a and a second light-emitting area 110b. The first light-emitting area 110a is closer to the center of the light-emitting unit area 101 than the second light-emitting area 110b, and the second light-emitting area 110b is arranged on the outer periphery of the first light-emitting area 110a (as Figure 3 shown); alternatively, the second light-emitting area 110b is arranged on the side of the first light-emitting area 110a far from the set position. In specific applications, the first light-emitting area 110a can be circular or polygonal, and the second light-emitting area 110b can be circular-ring-shaped or multi-sided-ring-shaped. The second light-emitting area 110b is arranged around the outer periphery of the first light-emitting area 110a, that is, the light-emitting unit 110 in the second light-emitting area 110b is relatively closer to the edge of the vertical-cavity surface-emitting laser than the light-emitting unit 110 in the first light-emitting area 110a. Of course, in specific applications, a third light-emitting area can also be arranged on the outer periphery of the second light-emitting area 110b. Similarly, a fourth light-emitting area can be arranged on the outer periphery of the third light-emitting area, and so on, which will not be elaborated here.

[0048] Specifically, the total resistance value of the current injection structure around each light-emitting unit 110 in the first light-emitting region 110a is R1, and the total resistance value of the current injection structure around each light-emitting unit 110 in the second light-emitting region 110b is R2, and R1 is less than R2. In this way, for the light-emitting units 110 relatively closer to the set position (the center of the light-emitting unit area), their current and power are relatively greater. It should be noted that the above total resistance refers to the total resistance value of the current injection structure corresponding to each light-emitting unit 110 (which may include multiple parallel current channels).

[0049] In this embodiment, one light-emitting unit 110 is provided in the first light-emitting region 110a, and the light-emitting unit 110 is disposed at the center point (as Figure 2 shown), or, multiple light-emitting units 110 are provided in the first light-emitting region 110a, and each of the light-emitting units 110 is evenly distributed along the circumferential direction with the center point as the center (as Figure 3 shown); that is, one or more light-emitting units 110 may be provided in the first light-emitting region 110a. In this embodiment, the light-emitting unit 110 in the first light-emitting region 110a is taken as an example. Of course, the number of light-emitting units 110 in the first light-emitting region 110a may also be three, four or other appropriate numbers. When multiple light-emitting units 110 are provided in the first light-emitting region 110a, each light-emitting unit 110 may be arranged according to a set rule or randomly arranged. Figure 4

[0050] Specifically, multiple light-emitting units 110 are provided in the second light-emitting region 110b. In this embodiment, the light-emitting units 110 in the second light-emitting region 110b are taken as six as an example. Of course, the number of light-emitting units 110 may also be 8, 10 or other appropriate numbers, and each of the light-emitting units 110 is evenly distributed along the circumferential direction with the center point as the center on the periphery of the first light-emitting region 110a, and each light-emitting unit 110 may be arranged according to a set rule or randomly arranged.

[0051] In specific applications, if more light-emitting units 110 or a larger-sized vertical cavity surface emitting laser are required, the light-emitting region further includes a third light-emitting region, and the third light-emitting region may be disposed around the periphery of the second light-emitting region 110b. Multiple light-emitting units 110 are provided in the third light-emitting region, and each of the light-emitting units 110 is evenly distributed along the circumferential direction with the center point as the center on the periphery of the second light-emitting region 110b, forming a three-ring structure.

[0052] In specific applications, each light-emitting unit 110 can adopt a double-ring or multi-ring arrangement. The inner ring can have one or more light-emitting units 110, and multiple light-emitting units 110 can be provided in the second ring and the third ring. Among them, the closer the light-emitting unit 110 is to the outer ring, the greater its corresponding resistance value, so as to reduce the current and power of the light-emitting unit 110 in the outer ring and prevent its emission angle from being too large.

[0053] Specifically, as Figures 1 to 5 shown, a first electrode 120 (which can be an Au layer for connecting to the positive electrode) is provided on one side of the device substrate 100. The first electrode 120 can be electrically connected to the first power supply access part 210. A second electrode (which can be an Au layer for connecting to the negative electrode) is provided on the other side of the device substrate 100. The current injection structure includes a conductive channel 112 electrically connected between the first electrode 120 and the second electrode. A plurality of the conductive channels 112 are provided around each of the light-emitting holes 111. The conductive channel 112 can be a (circular) cylindrical metal-filled hole, and a plurality of conductive channels 112 can be correspondingly provided around the outer periphery of each light-emitting hole 111. Figure 2 、 Figure 3 In, six conductive channels 112 are correspondingly provided around the outer periphery of each light-emitting hole 111.

[0054] The vertical cavity surface emitting laser includes a contact electrode layer 140. One end of the conductive channel 112 is connected to the first electrode 120, and the contact electrode layer 140 is a P-type ohmic contact layer connected to the other end of the conductive channel 112. A semiconductor contact layer 150 and an epitaxial layer 160 are sequentially disposed below the contact electrode layer 140, and the second electrode 170 (which can be a conductive metal layer for connecting to the negative electrode) is disposed on the bottom surface of the epitaxial layer 160. In a specific application, the epitaxial layer 160 includes a P-DBR layer 161, an optical confinement layer (OA layer) 162, a multi-quantum well layer (MQW layer) 163, and an N-DBR layer 164. The P-DBR layer 161, that is, a P-type distributed Bragg reflector, and the bottom N-DBR layer 164 together form an optical resonator to reflect light of a specific wavelength and enhance laser output. The P-DBR layer 161 can be composed of multiple layers of materials with different refractive indices, usually P-type doped. The optical confinement layer 162 (OA layer) is used to define the light-emitting area and current area of the vertical cavity surface emitting laser. The optical confinement layer 162 includes any one of an air column type optical confinement layer, an oxidation confinement type optical confinement layer, an ion implantation type optical confinement layer, and a tunnel junction type optical confinement layer. Among them, the air column type optical confinement layer realizes the confinement of current and light through air columns. The air columns are hollow structures formed by dry etching technology, and their refractive index is lower than that of the surrounding semiconductor materials, thereby effectively confining light in the central area. The oxidation confinement type optical confinement layer includes an unoxidized area made of AlGaAs material with a high aluminum component and an oxidized area made of alumina material. The oxidized area is located outside the unoxidized area, and the unoxidized area forms a light-emitting area for effective current injection. The ion implantation type optical confinement layer changes its electrical properties by implanting ions into the semiconductor material to form a high-resistance area, and the high-resistance area can limit the flow of current, thereby indirectly limiting the light generation area. The tunnel junction type optical confinement layer includes at least one highly doped N-type structure layer and at least one highly doped P-type structure layer. Specifically, a potential barrier is formed between the highly doped N-type structure layer and the highly doped P-type structure layer, and electrons are allowed to pass through the potential barrier through tunneling effect, thereby realizing the lateral confinement of current. In one embodiment, the materials of the N-type structure layer and the P-type structure layer are selected as AlxGa1-xAs, and the doping concentration of the N-type structure layer and the P-type structure layer is greater than 1e18 cm-3, where 0 ≤ x ≤ 1. The multi-quantum well layer 163 (MQW layer) serves as the active region, that is, the multi-quantum well active region (MQW Active Region), which is the region where laser is generated. The multi-quantum well structure is composed of alternating potential well layers and potential barrier layers. Carriers (electrons and holes) recombine in the potential well layers to generate photons and realize stimulated emission. The N-DBR layer 164 is an N-type distributed Bragg reflector, serving as the bottom reflector, and together with the top P-DBR layer 161 forms an optical resonator to reflect light of a specific wavelength and enhance laser output.The N-DBR layer 164 can be composed of multiple alternating layers of materials with different refractive indices and is typically N-type doped.

[0055] Specifically, the P-DBR layer 161 is located below the semiconductor contact layer 150, and the P-DBR layer 161, the optical confinement layer 162, the multiple quantum well layer 163, and the N-DBR layer 164 are arranged from top to bottom.

[0056] In a specific application, the contact electrode layer 140 can be a P-type ohmic contact layer or an N-type ohmic contact layer, corresponding to a vertical cavity surface emitting laser with front emission or back emission. In this embodiment, the contact electrode layer 140 is a P-type ohmic contact layer, and the vertical cavity surface emitting laser emits light from the front. When the contact electrode layer 140 is an N-type ohmic contact layer, the N-type ohmic contact layer is arranged closer to the second electrode 170 relative to the conductive channel 112, and the vertical cavity surface emitting laser is a vertical cavity surface emitting laser with back emission.

[0057] Specifically, the device substrate 100 further includes a passivation layer (which can be a SiN layer) 130. The conductive channel 112 penetrates through the passivation layer 130. The first electrode 120 (which can be a gold-plated layer) is disposed on one side of the passivation layer 130 and connected to the first end of the conductive channel 112, and a P-type ohmic contact layer is disposed on the other side of the passivation layer 130 and connected to the second end of the conductive channel 112.

[0058] As the first method of adjusting the resistance value, as Figure 3 shown, the cross-sectional area of the conductive channel 112 corresponding to the light-emitting unit 110 in the light-emitting region relatively closer to the set position (the diameter of the conductive channel 112 is D1) is larger than the cross-sectional area of the conductive channel 112 corresponding to the light-emitting unit 110 in the light-emitting region relatively farther from the set position (the diameter of the conductive channel 112 is D2), so that the resistance value of the conductive channel 112 in the first light-emitting region 110a is less than the resistance value of the conductive channel 112 in the second light-emitting region 110b. The number of conductive channels 112 corresponding to each light-emitting unit 110 in the first light-emitting region 110a can be equal to or greater than the number of conductive channels 112 corresponding to each light-emitting unit 110 in the second light-emitting region 110b. The number of conductive channels 112 corresponding to each light-emitting unit 110 in the first light-emitting region 110a can also be less than the number of conductive channels 112 corresponding to each light-emitting unit 110 in the second light-emitting region 110b, as long as the corresponding total resistance value meets the requirements.

[0059] As the second method for adjusting the resistance value, the number of conductive channels 112 corresponding to the light-emitting units 110 in the light-emitting region relatively close to the set position is greater than the number of conductive channels 112 corresponding to the light-emitting units 110 in the light-emitting region relatively far from the set position, which can also make the resistance value of the conductive channels 112 corresponding to the light-emitting units 110 in the first light-emitting region 110a less than the resistance value of the conductive channels 112 corresponding to the light-emitting units 110 in the second light-emitting region 110b.

[0060] As the third method for adjusting the resistance value, the conductivity of the conductive channels 112 corresponding to the light-emitting units 110 in the light-emitting region relatively close to the set position is less than the conductivity of the conductive channels 112 corresponding to the light-emitting units 110 in the light-emitting region relatively far from the set position, which can also make the resistance value of the conductive channels 112 corresponding to the light-emitting units 110 in the first light-emitting region 110a less than the resistance value of the conductive channels 112 corresponding to the light-emitting units 110 in the second light-emitting region 110b. In specific applications, different metal materials can be used for the conductive channels 112 corresponding to different light-emitting regions.

[0061] As the fourth method for adjusting the resistance value, as Figure 3 shown, the distance (L1) between the conductive channels 112 corresponding to the light-emitting units 110 and the light-emitting holes 111 in the light-emitting region relatively close to the set position is less than the distance (L2) between the conductive channels 112 corresponding to the light-emitting units 110 and the light-emitting holes 111 in the light-emitting region relatively far from the set position, which can also make the resistance value of the conductive channels 112 corresponding to the light-emitting units 110 in the first light-emitting region 110a less than the resistance value of the conductive channels 112 corresponding to the light-emitting units 110 in the second light-emitting region 110b.

[0062] The above methods for adjusting the resistance value can be used selectively, or at least two, three or all of them can be implemented simultaneously.

[0063] Specifically, the resistance value of the first electrode 120 corresponding to the light-emitting unit 110 in the light-emitting region relatively close to the set position is less than the resistance value of the first electrode 120 corresponding to the light-emitting unit 110 in the light-emitting region relatively far from the set position; in specific applications, at the connection between the first electrode 120 and the conductive channel 112 in the corresponding region, its thickness or width direction can be set regularly.

[0064] Alternatively, the resistance value of the contact electrode layer 140 corresponding to the light-emitting unit 110 in the light-emitting region relatively close to the set position is less than the resistance value of the contact electrode layer 140 corresponding to the light-emitting unit 110 in the light-emitting region relatively far from the set position. In specific applications, at the connection between the contact electrode layer 140 (such as a P-type ohmic contact layer) and the conductive channel 112 in the corresponding region, its thickness or width direction can be set regularly.

[0065] Specifically, the width of the contact electrode layer 140 or the first electrode 120 corresponding to the light-emitting unit 110 in the light-emitting region relatively close to the set position is greater than the width of the contact electrode layer 140 corresponding to the light-emitting unit 110 in the light-emitting region relatively far from the set position; or, the thickness of the contact electrode layer 140 or the first electrode 120 corresponding to the light-emitting unit 110 in the light-emitting region relatively close to the set position is greater than the thickness of the contact electrode layer 140 in the light-emitting region relatively far from the set position, which can also adjust the total resistance value of the light-emitting unit 110 in each light-emitting region, making the total resistance value of the light-emitting unit 110 near the periphery of the vertical cavity surface emitting laser relatively large.

[0066] An embodiment of the present invention further provides a method for manufacturing a vertical cavity surface emitting laser for manufacturing the above-mentioned vertical cavity surface emitting laser, including:

[0067] When manufacturing the current injection structure of the vertical cavity surface emitting laser, control the resistance value of the current injection structure at the set position of the device substrate 100 to be less than the resistance value of the current injection structure far from the set position;

[0068] Wherein, the set position is the center point of the light-emitting unit area 101, or the device substrate 100 is provided with a first power supply access part 210 on one side of the light-emitting unit area 101, and the set position is a position far from the first power supply access part 210.

[0069] In a specific application, a light-emitting unit area 101 for arranging the light-emitting units 110 is divided on the device substrate 100, and the light-emitting unit area 101 is divided into at least two light-emitting regions, so that the light-emitting regions are arranged from the set position to a position far from the set position;

[0070] In a specific application, light-emitting units 110 are designed in each of the light-emitting regions. Each light-emitting unit 110 includes a light-emitting hole 111 and a current injection structure disposed around the light-emitting hole 111, so that the resistance value of the current injection structure corresponding to the light-emitting unit 110 in the light-emitting region relatively close to the set position is less than the resistance value of the current injection structure corresponding to the light-emitting unit 110 in the light-emitting region relatively far from the set position.

[0071] If the resistance values of the light-emitting units 110 in a vertical-cavity surface-emitting laser are all the same, due to reasons such as the length of the current path, during the actual current injection process, the distribution of the current in each light-emitting unit 110 is uneven. Moreover, for the light-emitting holes 111 on the periphery of the vertical-cavity surface-emitting laser, the higher the injection current, the higher the injection current carried by the outermost light-emitting unit 110, and its corresponding emission angle is large, which affects the far-field divergence angle. When the vertical-cavity surface-emitting laser operates stably, its injection current is constant. In this embodiment, by reducing the resistance value of the current injection structure corresponding to the light-emitting holes 111 in the central part of the light-emitting region (which can be achieved by increasing the size of the conductive channels 112, etc.), the resistance value corresponding to the light-emitting unit 110 at the central position is deliberately reduced, so that the current can be concentrated relatively towards the central part of the light-emitting region, thereby achieving the purpose of adjusting the current injection uniformity of different light-emitting units 110 at different positions, and further avoiding the phenomenon that the outermost light-emitting holes prematurely appear high-order modes due to uneven injection current. Of course, a similar effect can also be achieved by increasing the number of conductive channels 112 around the light-emitting holes 111 at the central position of the device or increasing the width of the P ohmic contact layer, etc.

[0072] As Figure 5 The arrow shown in the figure is the current injection direction of the vertical-cavity surface-emitting laser. It can be seen that after the current passes through the conductive channels 112, it passes through the contact electrode layer 140 and the semiconductor contact layer 150, and then flows from the hole position of the optical confinement layer 162 to the multi-quantum well layer 163 to achieve laser excitation.

[0073] The embodiment of the present invention also provides a laser device, and the laser device includes a vertical-cavity surface-emitting laser as described above.

[0074] The embodiment of the present invention also provides a light source for a lidar system, including at least one vertical-cavity surface-emitting laser as described above.

[0075] The embodiment of the present invention also provides a lidar system, including a transmitting component and a receiving component, and the transmitting component uses the light source for a lidar system as described above.

[0076] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, or improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A vertical cavity surface emitting laser, characterized in that, It includes a device substrate, the device substrate has a light-emitting unit area, the light-emitting unit area includes at least two light-emitting regions arranged away from the set position from a self-set position, and at least one light-emitting unit is provided in each light-emitting region; Each light-emitting unit includes a light-emitting hole and a current injection structure arranged around the light-emitting hole; the resistance value of the current injection structure corresponding to the light-emitting unit in the light-emitting region relatively closer to the set position is less than the resistance value of the current injection structure corresponding to the light-emitting unit in the light-emitting region relatively farther from the set position; The set position is the center point of the light-emitting unit area, or, the device substrate is provided with a first power supply access part on one side of the light-emitting unit area, and the set position is a position away from the first power supply access part.

2. A vertical cavity surface emitting laser according to claim 1, wherein, The light-emitting region includes a first light-emitting region and a second light-emitting region. The first light-emitting region is closer to the center of the light-emitting unit area than the second light-emitting region. The second light-emitting region is provided on the outer periphery of the first light-emitting region, or, the second light-emitting region is provided on the side of the first light-emitting region away from the set position; The total resistance value of the current injection structures around each light-emitting unit in the first light-emitting region is R1, the total resistance value of the current injection structures around each light-emitting unit in the second light-emitting region is R2, and R1 is less than R2.

3. A vertical cavity surface emitting laser according to claim 2, wherein, One light-emitting unit is provided in the first light-emitting region, and the light-emitting unit is provided at the center point, or, multiple light-emitting units are provided in the first light-emitting region, and each light-emitting unit is evenly distributed along the circumferential direction with the center point as the center; Multiple light-emitting units are provided in the second light-emitting region, and each light-emitting unit is evenly distributed along the circumferential direction with the center point as the center.

4. The vertical cavity surface emitting laser according to claim 3, characterized in that, The light-emitting region further includes a third light-emitting region. Multiple light-emitting units are provided in the third light-emitting region, and each light-emitting unit is evenly distributed along the circumferential direction on the periphery of the second light-emitting region with the center point as the center.

5. A vertical cavity surface emitting laser according to any one of claims 1 to 4, wherein, A first electrode is provided on one side of the device substrate, a second electrode is provided on the other side of the device substrate, the current injection structure includes a conductive channel provided between the first electrode and the second electrode, and multiple conductive channels are provided around the periphery of each light-emitting hole; The vertical cavity surface emitting laser includes a contact electrode layer; One end of the conductive channel is connected to the first electrode, and the contact electrode layer is a P-type ohmic contact layer connected to the other end of the conductive channel, or, the contact electrode layer is an N-type ohmic contact layer provided relatively closer to the second electrode than the conductive channel.

6. A vertical cavity surface emitting laser according to claim 5, wherein, The cross-sectional area of the conductive channel corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is larger than the cross-sectional area of the conductive channel corresponding to the light-emitting unit in the light-emitting region relatively far from the set position; Or, the number of conductive channels corresponding to the light-emitting units in the light-emitting region relatively close to the set position is larger than the number of conductive channels corresponding to the light-emitting units in the light-emitting region relatively far from the set position; Or, the conductivity of the conductive channel corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is smaller than the conductivity of the conductive channel corresponding to the light-emitting unit in the light-emitting region relatively far from the set position; Or, the distance between the conductive channel corresponding to the light-emitting unit and the light-emitting hole in the light-emitting region relatively close to the set position is smaller than the distance between the conductive channel corresponding to the light-emitting unit and the light-emitting hole in the light-emitting region relatively far from the set position.

7. A vertical cavity surface emitting laser according to claim 5, wherein the resistance value of the first electrode corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is smaller than the resistance value of the first electrode corresponding to the light-emitting unit in the light-emitting region relatively far from the set position; Or / and, the resistance value of the contact electrode layer corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is smaller than the resistance value of the contact electrode layer corresponding to the light-emitting unit in the light-emitting region relatively far from the set position.

8. A vertical cavity surface emitting laser according to claim 7, wherein the width of the contact electrode layer or the first electrode corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is larger than the width of the contact electrode layer corresponding to the light-emitting unit in the light-emitting region relatively far from the set position; Or, the thickness of the contact electrode layer or the first electrode corresponding to the light-emitting unit in the light-emitting region relatively close to the set position is larger than the thickness of the contact electrode layer in the light-emitting region relatively far from the set position.

9. A vertical cavity surface emitting laser according to claim 5, wherein the device substrate includes a passivation layer, the conductive channel penetrates through the passivation layer, the first electrode is disposed on one side of the passivation layer and connected to the first end of the conductive channel, the contact electrode layer is a P-type ohmic contact layer and is disposed on the other side of the passivation layer and connected to the second end of the conductive channel; a semiconductor contact layer and an epitaxial layer are sequentially disposed below the contact electrode layer; the epitaxial layer includes a P-DBR layer, a photoelectric confinement layer, a multi-quantum well layer, and an N-DBR layer sequentially arranged from top to bottom.

10. A method for fabricating a vertical cavity surface emitting laser, characterized in that, For manufacturing a vertical cavity surface emitting laser according to any one of claims 1 to 9, including: When manufacturing the current injection structure of the vertical cavity surface emitting laser, controlling the resistance value of the current injection structure at the set position to be smaller than the resistance value of the current injection structure far from the set position; Wherein, the set position is the center point of the light-emitting unit region, or, the device substrate is provided with a first power supply access portion on one side of the light-emitting unit region, and the set position is a position far from the first power supply access portion.

11. A light source for a lidar system, characterized in that, Comprising at least one vertical cavity surface emitting laser as described in any one of claims 1-9.

12. A lidar system, characterized in that, Comprising a transmitting component for emitting a light source and a receiving component for receiving the light source, wherein the transmitting component employs the light source for a lidar system as described in claim 11.

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