Vertical cavity surface emitting laser, preparation method, laser radar system and light source of laser radar system

Abstract

The invention relates to the technical field of vertical-cavity surface-emitting lasers, and provides a vertical-cavity surface-emitting laser, a preparation method, a laser radar system and a light source of the laser radar system. The vertical-cavity surface-emitting laser comprises a device substrate, the device substrate is provided with a light-emitting unit area, the light-emitting unit area comprises at least two light-emitting areas which are arranged from a set position to a position far away from the set position, and at least one light-emitting unit is arranged in each light-emitting area; each light-emitting unit comprises 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 area relatively close to the set position is smaller than the resistance value of the current injection structure corresponding to the light-emitting unit in the light-emitting area relatively far away from the set position, so that the phenomenon that the peripheral light-emitting hole has a high-order mode too early due to non-uniform injection current is avoided; the problem of a far-field divergence angle is solved, and the use performance of the vertical-cavity surface-emitting laser is ensured.

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 the 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, vertical cavity surface emitting lasers mostly reduce the far-field divergence angle at the cost of sacrificing power. Relatively, 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 uneven injection current, which in turn increases the loss of unit optical power of the light-emitting holes, and 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 away from the set position from a self-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; 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; 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 far from the first power supply access part.

[0005] 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 far from the set position; The total resistance value of the current injection structure around each light-emitting unit in the first light-emitting region is R1, and 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.

[0006] Optionally, one light-emitting unit is provided in the first light-emitting region, and the light-emitting unit is disposed at the center point. Alternatively, a plurality of light-emitting units are provided in the first light-emitting region, and the light-emitting units are evenly distributed along the circumferential direction with the center point as the center; A plurality of light-emitting units are provided in the second light-emitting region, and the light-emitting units are evenly distributed along the circumferential direction with the center point as the center. Optionally, the light-emitting region further includes a third light-emitting region, and a plurality of light-emitting units are provided in the third light-emitting region, and the light-emitting units are evenly distributed along the circumferential direction with the center point as the center on the periphery of the second light-emitting region. Optionally, 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 disposed between the first electrode and the second electrode, and a plurality of the conductive channels are provided around each of the light-emitting holes; 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 disposed relatively closer to the second electrode than the conductive channel.

[0007] 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; Alternatively, 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; Alternatively, 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; Alternatively, the distance between the conductive channel corresponding to the light-emitting unit and the light-emitting hole in the light-emitting region relatively closer to the set position is less than the distance between the conductive channel corresponding to the light-emitting unit and the light-emitting hole in the light-emitting region relatively farther from the set position. Optionally, the resistance value of the first electrode 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 first electrode corresponding to the light-emitting unit in the light-emitting region relatively farther from the set position; 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 less 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. 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; 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. 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, 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. 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: 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 less 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. The present invention also provides a light source for a lidar system, including at least one of the above-mentioned vertical cavity surface emitting lasers.

[0008] The present invention also provides a lidar system, including a transmitting component for emitting a light source and a receiving component for receiving the light source, and the transmitting component uses the above-mentioned light source for a lidar system.

[0009] 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 a current injection structure corresponding to a light emitting hole in the central part of a light emitting region, so as to reduce the resistance value corresponding to a light emitting unit at the central position, enable current to concentrate 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 at different positions, and further avoiding the phenomenon that higher-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 problem that the emission angle of the light emitting unit in the edge region is too large and 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 supply access part, and the light emitting unit with a relatively large resistance value has a relatively shorter path from the first power supply 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use 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.

[0011] Figure 1 is a top view of a vertical cavity surface emitting laser provided by an embodiment of the present invention; Figure 2 is a first layout schematic diagram of light emitting units in a light emitting unit region of a vertical cavity surface emitting laser provided by an embodiment of the present invention; Figure 3 is a second layout schematic diagram of light emitting units in a light emitting unit region of a vertical cavity surface emitting laser provided by an embodiment of the present invention; Figure 4 is a third layout schematic diagram of light emitting units in a light emitting unit region of a vertical cavity surface emitting laser provided by an embodiment of the present invention; Figure 5 is Figure 1 a schematic cross-sectional view of the A-A cross-section in.

[0012] Description of the reference numerals: 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, multi-quantum well layer; 164, N-DBR layer; 170, second electrode. Detailed implementation manners

[0013] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, 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.

[0014] It should be noted that the terms "arranged" and "connected" should be understood in a broad sense. For example, they can be directly arranged or connected, or indirectly arranged or connected through intermediate components or intermediate structures.

[0015] In addition, in the embodiments of the present invention, if there are terms indicating orientation or positional relationships such as "longitudinal", "lateral", "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 cannot be understood as limitations on the present invention. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0016] In the various specific technical features and embodiments described in the detailed implementation manners, they can be combined in any appropriate manner without conflict. For example, different embodiments can be formed by combining different specific technical features / embodiments. To avoid unnecessary repetition, the various possible combination methods of the specific technical features / embodiments in the present invention will not be described separately.

[0017] As Figure 1 and Figure 2 shown, a vertical cavity surface emitting laser provided by an embodiment of the present invention includes a device substrate 100. The device substrate 100 has a light-emitting unit area 101. The light-emitting unit area 101 includes at least two light-emitting areas, and each light-emitting area is arranged away from the set position from the set position.

[0018] At least one light-emitting unit 110 is provided in each of the light-emitting regions; each light-emitting unit 110 includes a light-emitting hole 111 and a current injection structure, and the current injection structure can be disposed 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 (such as Figure 2 the point O shown in

[0019] ), or the device substrate 100 is provided with a first power supply access portion 210 (which can be used to connect to the positive electrode of the power supply) on one side of the light-emitting unit region 101, and the set position is a position far from the first power supply access portion 210, that is, the light-emitting unit 110 far from the center point of the light-emitting unit region 101 or far from the first power supply access portion 210 has a relatively small corresponding resistance value. Each light-emitting hole 111 and the corresponding current injection structure can be regarded as a resistor connected in parallel between the positive electrode and the negative electrode of the power supply.

[0020] Specifically, as shown in Figures 1 to 3 , the light-emitting region includes a first light-emitting region 110a and a second light-emitting region 110b. The first light-emitting region 110a is closer to the center of the light-emitting unit region 101 than the second light-emitting region 110b, and the second light-emitting region 110b is disposed on the outer periphery of the first light-emitting region 110a (such asFigure 3 as shown); alternatively, the second light-emitting region 110b is disposed on a side of the first light-emitting region 110a away from the set position. In a specific application, the first light-emitting region 110a may be circular or polygonal, and the second light-emitting region 110b may be circular ring-shaped or multi-sided ring-shaped. The second light-emitting region 110b is disposed around the periphery of the first light-emitting region 110a, that is, the light-emitting units 110 in the second light-emitting region 110b are relatively closer to the edge of the vertical cavity surface emitting laser than the light-emitting units 110 in the first light-emitting region 110a. Of course, in a specific application, a third light-emitting region may be disposed around the periphery of the second light-emitting region 110b. Similarly, a fourth light-emitting region may be disposed around the periphery of the third light-emitting region, and so on, which will not be elaborated herein.

[0021] 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).

[0022] In this embodiment, one light-emitting unit 110 is disposed in the first light-emitting region 110a, and the light-emitting unit 110 is disposed at the center point (as Figure 2 shown), or, a plurality of light-emitting units 110 are disposed 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 disposed 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 or four or other appropriate numbers. When a plurality of light-emitting units 110 are disposed 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 shown); that is, one or more light-emitting units 110 may be disposed 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 or four or other appropriate numbers. When a plurality of light-emitting units 110 are disposed in the first light-emitting region 110a, each light-emitting unit 110 may be arranged according to a set rule or randomly arranged.

[0023] Specifically, a plurality of light-emitting units 110 are disposed in the second light-emitting region 110b. In this embodiment, the number of light-emitting units 110 in the second light-emitting region 110b is taken as six as an example. Of course, the number of light-emitting units 110 may also be 8 or 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.

[0024] In specific applications, if more light-emitting units 110 or a vertical cavity surface emitting laser with a larger size is required, the light-emitting region further includes a third light-emitting region, and the third light-emitting region can be disposed around the periphery of the second light-emitting region 110b. A plurality of light-emitting units 110 are disposed in the third light-emitting region, and each of the light-emitting units 110 is uniformly distributed in the circumferential direction around the second light-emitting region 110b with the center point as the center, forming a three-ring structure.

[0025] In specific applications, that is, 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 a plurality of light-emitting units 110 can be disposed in both the second ring and the third ring. Among them, the closer the light-emitting unit 110 is to the outer ring, the larger its corresponding resistance value, so as to reduce the current and power of the outer-ring light-emitting unit 110 and prevent its emission angle from being too large.

[0026] Specifically, as Figures 1 to 5 shown, a first electrode 120 (which can be an Au layer for connecting to the positive electrode) is disposed on one side of the device substrate 100. The first electrode 120 can be electrically connected to the first power supply access portion 210. A second electrode (which can be an Au layer for connecting to the negative electrode) is disposed 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 disposed around each of the light-emitting holes 111. The conductive channels 112 can be (cylindrical) metal-filled holes, and a plurality of conductive channels 112 can be correspondingly disposed around the outer periphery of each light-emitting hole 111. Figure 2 、 Figure 3 In

[0027] 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. Below the contact electrode layer 140, a semiconductor contact layer 150 and an epitaxial layer 160 are sequentially arranged. The bottom surface of the epitaxial layer 160 is provided with the second electrode 170 (which can be a conductive metal layer for connecting to the negative electrode). In specific applications, 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, namely the 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 indexes, 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 pillar 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 pillar type optical confinement layer realizes the confinement of current and light through air pillars. The air pillars are hollow structures formed by dry etching technology, and their refractive index is lower than that of the surrounding semiconductor materials, thus effectively confining the 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, which can limit the flow of current and thus indirectly limit 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 the tunnel effect, thus 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 may be composed of multiple layers of materials with different refractive indices, usually N-type doped.

[0028] 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.

[0029] 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.

[0030] 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 plating 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.

[0031] 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.

[0032] As the second way to adjust the resistance value, the number of conductive channels 112 corresponding to the light-emitting units 110 in the light-emitting area 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 area 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 area 110a less than the resistance value of the conductive channels 112 corresponding to the light-emitting units 110 in the second light-emitting area 110b.

[0033] As the third way to adjust the resistance value, the conductivity of the conductive channels 112 corresponding to the light-emitting units 110 in the light-emitting area 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 area relatively far from the set position, which can also make the resistance value corresponding to the light-emitting units 110 in the first light-emitting area 110a less than the resistance value corresponding to the light-emitting units 110 in the second light-emitting area 110b. In specific applications, different metal materials can be used for the conductive channels 112 corresponding to different light-emitting areas.

[0034] As the fourth way to adjust 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 area 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 area relatively far from the set position, which can also make the resistance value corresponding to the light-emitting units 110 in the first light-emitting area 110a less than the resistance value corresponding to the light-emitting units 110 in the second light-emitting area 110b.

[0035] The above ways to adjust the resistance value can be used selectively, or at least two, three or all of them can be implemented simultaneously.

[0036] Specifically, the resistance value of the first electrode 120 corresponding to the light-emitting units 110 in the light-emitting area relatively close to the set position is less than the resistance value of the first electrode 120 corresponding to the light-emitting units 110 in the light-emitting area relatively far from the set position; in specific applications, at the connection between the first electrode 120 and the conductive channels 112 in the corresponding area, its thickness or width direction can be set regularly.

[0037] Or, the resistance value of the contact electrode layer 140 corresponding to the light-emitting units 110 in the light-emitting area relatively close to the set position is less than the resistance value of the contact electrode layer 140 corresponding to the light-emitting units 110 in the light-emitting area 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 channels 112 in the corresponding area, its thickness or width direction can be set regularly.

[0038] 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; alternatively, 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.

[0039] 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: 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; 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.

[0040] 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 away from the set position from the set position; In a specific application, light-emitting units 110 are designed 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 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.

[0041] 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 the corresponding larger the emission angle, 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 area (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 area, 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 exhibit 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.

[0042] 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.

[0043] An embodiment of the present invention further provides a laser device, and the laser device includes a vertical-cavity surface-emitting laser as described above.

[0044] An embodiment of the present invention further provides a light source for a lidar system, including at least one vertical-cavity surface-emitting laser as described above.

[0045] An embodiment of the present invention further 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.

[0046] 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 principles of the present invention shall be included within 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 provided 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 access part on one side of the light-emitting unit area, and the set position is a position away from the first power access part.

2. The vertical cavity surface emitting laser according to claim 1, characterized in that, 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. The vertical cavity surface emitting laser according to claim 2, characterized in that, 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 outer periphery of the second light-emitting region with the center point as the center.

5. The vertical cavity surface emitting laser according to any one of claims 1 to 4, characterized in that, 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. The vertical cavity surface emitting laser according to claim 5, characterized in that, 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 greater 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; Or, the number of conductive channels corresponding to the light-emitting unit in the light-emitting region relatively closer to the set position is greater than the number of conductive channels corresponding to the light-emitting unit in the light-emitting region relatively farther from the set position; Alternatively, 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; Alternatively, the distance between the conductive channel corresponding to the light-emitting unit and the light-emitting hole in the light-emitting region relatively closer to the set position is less than the distance between the conductive channel corresponding to the light-emitting unit and the light-emitting hole in the light-emitting region relatively farther from the set position.

7. The vertical cavity surface emitting laser according to claim 5, characterized in that, The resistance value of the first electrode 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 first electrode corresponding to the light-emitting unit in the light-emitting region relatively farther from the set position; Alternatively, and / or, the resistance value of the contact electrode layer 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 contact electrode layer corresponding to the light-emitting unit in the light-emitting region relatively farther from the set position.

8. The vertical cavity surface emitting laser according to claim 7, characterized in that, The width of the contact electrode layer or the first electrode corresponding to the light-emitting unit in the light-emitting region relatively closer 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 farther from the set position; Alternatively, the thickness of the contact electrode layer or the first electrode corresponding to the light-emitting unit in the light-emitting region relatively closer to the set position is greater than the thickness of the contact electrode layer in the light-emitting region relatively farther from the set position.

9. The vertical cavity surface emitting laser according to claim 5, characterized in that, The device substrate includes a passivation layer, the conductive channel penetrates through the passivation layer, and 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 under 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 manufacturing a vertical cavity surface emitting laser, characterized in that, A device for manufacturing a vertical cavity surface emitting laser according to any one of claims 1 to 9, comprising: 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 less than the resistance value of the current injection structure away from the set position; Wherein, 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.

11. A light source for a lidar system, characterized in that, Comprising at least one vertical cavity surface emitting laser according to 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, and the transmitting component uses the light source for a lidar system according to claim 11.

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