Vertical cavity surface emitting laser and preparation method, laser radar 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 laser radar system and a light source thereof. The vertical cavity surface emitting laser includes a device base, which includes a substrate and a plurality of light-emitting units arranged on the substrate, each light-emitting unit being separated by a groove; each light-emitting unit includes an epitaxial layer and an ohmic contact layer sequentially arranged on the substrate; the groove is opened in the epitaxial layer; a current blocking portion embedded in the epitaxial layer is provided below the ohmic contact layer corresponding to some or all of the light-emitting units; the current blocking portion is configured to control the current injected into the epitaxial layer by at least one of the light-emitting units via the ohmic contact layer to be different from the current injected into the epitaxial layer by the remaining light-emitting units via the ohmic contact layer; the phenomenon of premature high-order modes in the peripheral light-emitting holes due to uneven injection current is avoided, the problem of far-field divergence angle is improved, and the performance of the vertical cavity surface emitting laser is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of vertical cavity surface emitting lasers, and in particular relates to a vertical cavity surface emitting laser and a preparation method thereof, a laser radar 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 constrain each other, and these two indicators are very important for VCSELs. Usually, in order to pursue a small divergence angle, vertical cavity surface emitting lasers often reduce the far-field divergence angle at the expense of power. Relatively speaking, in order to compensate for the loss of optical power of the vertical cavity surface emitting laser, the number of light-emitting holes on the vertical cavity surface emitting laser has to be increased. The increase in light-emitting holes will bring about problems such as increased chip size and heat generation, and will also lead to uneven injection current, thereby increasing the loss of unit optical power of the light-emitting hole. The uneven current injection will also lead to an increase in the far-field divergence angle, affecting the performance of the vertical cavity surface emitting laser. Summary of the Invention

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

[0004] The technical solution of the present invention is:

[0005] A vertical cavity surface emitting laser comprises a device base, wherein the device base comprises a substrate and a plurality of light emitting units arranged on the substrate, wherein each of the light emitting units is separated by a groove;

[0006] Each light-emitting unit includes an epitaxial layer and an ohmic contact layer sequentially arranged on the substrate; the groove is opened in the epitaxial layer; a current blocking portion embedded in the epitaxial layer is provided under the ohmic contact layer corresponding to some or all of the light-emitting units; the current blocking portion is configured to control the current injected into the epitaxial layer via the ohmic contact layer of at least one light-emitting unit to be different from the current injected into the epitaxial layer via the ohmic contact layer by the remaining light-emitting units.

[0007] Optionally, the device substrate has a light-emitting unit area, the light-emitting unit area includes at least two light-emitting regions arranged from a set position to away from the set position, and each light-emitting region is provided with at least one light-emitting unit;

[0008] The set position is the center point of the light emitting unit area, or the device substrate is provided with a first power supply input portion located on one side of the light emitting unit area, and the set position is a position away from the first power supply input portion.

[0009] Optionally, a thickness of the current blocking portion relatively far from the set position is greater than a thickness of the current blocking portion relatively close to the set position;

[0010] Alternatively, the width of the current blocking portion relatively far from the set position is greater than the width of the current blocking portion relatively close to the set position;

[0011] Alternatively, the material conductivity of the current blocking portion relatively far from the set position is lower than the material conductivity of the current blocking portion relatively close to the set position.

[0012] Optionally, except for the light-emitting units in the light-emitting area close to the set position, the rest of the light-emitting units are provided with the current blocking portion.

[0013] Optionally, the light-emitting area includes a first light-emitting area and a second light-emitting area, the first light-emitting area is closer to the center of the light-emitting unit area relative to the second light-emitting area, and the second light-emitting area is arranged on the periphery of the first light-emitting area, or the second light-emitting area is arranged on a side of the first light-emitting area away from the set position;

[0014] The current blocking portion is provided under each light-emitting unit in the first light-emitting area, and the total resistance value of the light-emitting unit is R1. The current blocking portion is provided under each light-emitting unit in the second light-emitting area, and the total resistance value of the light-emitting unit is R2, and R1 is smaller than R2.

[0015] Optionally, each of the light-emitting units includes a light-emitting hole and a current injection structure arranged around the light-emitting hole; a first electrode is provided on one side of the device substrate, and 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 a plurality of the conductive channels are provided around each light-emitting hole;

[0016] The current blocking portion is in contact with the ohmic contact layer;

[0017] One end of the conductive channel is connected to the first electrode, and the ohmic contact layer is a P-type ohmic contact layer connected to the other end of the conductive channel.

[0018] Optionally, one side of the P-type ohmic contact layer is connected to the conductive channel, the current blocking portion is arranged on the other side of the P-type ohmic contact layer, and the current blocking portion is layered and has a hollow hole, and the hollow hole is coaxially arranged corresponding to the light-emitting hole.

[0019] Optionally, the inner diameter of the hollow hole is larger than the aperture of the light-emitting hole, and the aperture of the hollow hole relatively close to the set position is larger than the aperture of the hollow hole relatively far from the set position.

[0020] Optionally, the device substrate includes a passivation layer, the conductive channel runs through the passivation layer, the first electrode is provided on one side of the passivation layer and connected to the first end of the conductive channel,

[0021] The ohmic contact layer is disposed on the other side of the passivation layer and connected to the second end of the conductive path;

[0022] The epitaxial layer includes a semiconductor contact layer, a P-DBR layer, a photoelectric confinement layer, a multi-quantum well layer, and an N-DBR layer arranged in order from top to bottom. Optionally, the current blocking portion is made of an insulating material or a semi-insulating material;

[0023] Alternatively, the semiconductor contact layer is provided with an etching groove, and the current blocking portion is filled in the etching groove and is in contact with the ohmic contact layer.

[0024] The present invention also provides a method for preparing a vertical cavity surface emitting laser, which is used to prepare the above-mentioned vertical cavity surface emitting laser, comprising:

[0025] When the light-emitting units of the vertical cavity surface emitting laser are manufactured, a current blocking portion embedded in the epitaxial layer is provided below the ohmic contact layer corresponding to some or all of the light-emitting units; the current blocking portion is configured so that the current injected into the epitaxial layer via the ohmic contact layer by at least one of the light-emitting units is different from the current injected into the epitaxial layer via the ohmic contact layer by the remaining light-emitting units.

[0026] The present invention also provides a light source for a laser radar system, comprising at least one of the above-mentioned vertical cavity surface emitting lasers.

[0027] The present invention also provides a laser radar system, comprising a transmitting component for transmitting a light source and a receiving component for receiving the light source, wherein the transmitting component adopts the above-mentioned light source for the laser radar system.

[0028] The present invention provides a vertical cavity surface emitting laser (VCSEL), a preparation method, a lidar system, and a light source thereof. By disposing a current blocking portion of larger size / resistance at a location relatively far from a set position, the overall resistance of the light-emitting units in the center of the light-emitting region is reduced. This intentionally lowers the resistance corresponding to the light-emitting units in the center, allowing the current to be relatively concentrated toward the center of the light-emitting region, thereby achieving the purpose of adjusting the current injection uniformity of different light-emitting units at different locations, thereby avoiding the phenomenon of premature high-order modes in peripheral light-emitting holes due to uneven injection current. Light-emitting units with relatively small resistance can carry higher current and power, while light-emitting units with relatively large resistance carry relatively low current and power, thus preventing the light-emitting angles of light-emitting units in the edge region from being too large and affecting the far-field divergence angle of the VCSEL. Moreover, the light-emitting unit with relatively small resistance is relatively farther away from the path of the first power access part, and the light-emitting unit with relatively large resistance is relatively closer to the path of the first power access part. The complementary resistance values ​​are also conducive to making 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. The far-field divergence angle can be reduced without sacrificing power, thereby ensuring the performance of the vertical cavity surface emitting laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 is a top view of a vertical cavity surface emitting laser provided by an embodiment of the present invention;

[0031] Figure 2 Schematic diagram of the arrangement of light-emitting units in a light-emitting unit area of ​​a vertical cavity surface emitting laser provided by an embodiment of the present invention;

[0032] Figure 3 yes Figure 1 Schematic cross-section of the AA section;

[0033] Figure 4 It is a partial cross-sectional schematic diagram of a vertical cavity surface emitting laser provided by an embodiment of the present invention.

[0034] Description of reference numerals:

[0035] 100. Device substrate; 101. Light-emitting unit area; 110. Light-emitting unit; 111. Light-emitting hole; 210. First power supply access part; 120. First electrode; 112. Conductive channel; 130. Passivation layer; 140. Ohmic contact layer; 150. Semiconductor contact layer; 160. Epitaxial layer; 161. P-DBR layer; 162. Photoelectric confinement layer; 163. Multi-quantum well layer; 164. N-DBR layer; 170. Second electrode; 190. Current blocking part. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, 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 intended to limit the present invention.

[0037] It should be noted that the terms "setting" and "connecting" should be understood in a broad sense. For example, it can be directly setting or connecting, or it can be indirectly setting or connecting through a central component or a central structure.

[0038] In addition, if there are terms such as "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating orientation or positional relationships in the embodiments of the present invention, they are based on the orientation or positional relationships shown in the drawings or the conventional placement state or usage state, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structure, feature, device or element referred to must have a specific orientation or positional relationship, nor must it be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0039] 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.

[0040] like Figure 1 and Figure 2As shown, an embodiment of the present invention provides a vertical cavity surface emitting laser, comprising a device base 100, the device base 100 comprising a substrate 200 and a plurality of light-emitting units 110 disposed on the substrate 200, each light-emitting unit 110 being separated by a trench. Each light-emitting unit 110 comprises an epitaxial layer 160 and an ohmic contact layer 140 sequentially disposed on the substrate 200; the trench is defined in the epitaxial layer 160; a current blocking portion 190 embedded in the epitaxial layer 160 is disposed below the ohmic contact layer 140 corresponding to some or all of the light-emitting units 110; the current blocking portion 190 is configured to control the current injected into the epitaxial layer 160 by at least one light-emitting unit 110 via the ohmic contact layer 140 to be different from the current injected into the epitaxial layer 160 by the remaining light-emitting units 110 via the ohmic contact layer 140. After the current blocking portion 190 is formed, each of the light-emitting units 110 meets the following condition: the current injected into the epitaxial layer 160 by at least one light-emitting unit 110 via the ohmic contact layer 140 is different from the current injected into the epitaxial layer 160 by the remaining light-emitting units 110 via the ohmic contact layer 140. By adjusting the current carrying capacity of the light-emitting units 110, the current carrying capacity of each light-emitting unit 110 is balanced and consistent, preventing the light-emitting angle of the light-emitting units 110 in a local area (particularly the edge area) from being too large, thereby affecting the far-field divergence angle of the vertical cavity surface emitting laser.

[0041] Specifically, the device substrate 100 has a light-emitting unit area 101 , and the light-emitting unit area 101 includes at least two light-emitting regions, and each light-emitting region is arranged from a set position to a position away from the set position.

[0042] At least one light-emitting unit 110 is provided in each of the light-emitting areas; some or all of the light-emitting units 110 are correspondingly provided with a current blocking portion (current blocking layer) 190, and the difference in size and / or conductivity of the current blocking portion makes the overall resistance value of the light-emitting unit 110 far away from the set position greater than the overall resistance value of the light-emitting unit 110 relatively close to the set position.

[0043] The overall resistance value of the light emitting unit 110 in the light emitting area relatively close to the set position is smaller than the overall resistance value corresponding to the light emitting unit 110 in the light emitting area relatively far from the set position. The set position can be the center point of the light emitting unit area 101 (such as Figure 2Alternatively, 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 set position is a position away from the first power supply connection portion 210, that is, 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 unit 110 can be regarded as a resistor connected in parallel between the positive and negative power supply electrodes.

[0044] Light-emitting units 110 with relatively low resistance can carry higher currents and powers, while light-emitting units 110 with relatively high resistance can carry relatively low currents and powers, preventing the light-emitting units 110 in edge regions from having excessively large emission angles, which could affect the far-field divergence angle of the vertical-cavity surface-emitting laser. Furthermore, light-emitting units 110 with relatively low resistance are located farther from the path of the first power supply connection 210, while light-emitting units 110 with relatively high resistance are located closer to the path of the first power supply connection 210. This complementary resistance also helps to even out the injected current. In this way, the resistance value of the current injection structure corresponding to the light-emitting unit 110 close to the set position is smaller, and the resistance value of the current injection structure corresponding to the light-emitting unit 110 far from the set position is larger, so that the battery tends to flow toward the light-emitting unit 110 at the set position. In this embodiment, the set position is taken as the center of the light-emitting unit area 101 as an example. In this way, the current tends to flow toward the light-emitting unit 110 in the central area, so that the current and power carried by the light-emitting unit 110 in the central area are relatively large, and the current and power carried by the light-emitting unit 110 in the peripheral area are 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. The far-field divergence angle can be reduced without sacrificing power, thereby ensuring the performance of the vertical cavity surface emitting laser.

[0045] In a specific application, the size or conductivity of the current blocking portion 190 relatively far from the set position is greater than the size or conductivity of the current blocking portion 190 relatively close to the set position, which can be adjusted by adjusting the material and / or size of the current blocking portion 190.

[0046] In a specific application, as a first adjustment method, the thickness of the current blocking part 190 that is relatively far away from the set position is greater than the thickness of the current blocking part 190 that is relatively close to the set position, that is, the current blocking part 190 with a thicker axial dimension corresponds to a larger overall resistance value of the light-emitting unit 110.

[0047] As a second adjustment method, the width of the current blocking portion 190 relatively far away from the set position is greater than the width of the current blocking portion 190 relatively close to the set position, that is, the current blocking portion 190 with a larger radial dimension corresponds to a larger overall resistance value of the light-emitting unit 110.

[0048] As a third adjustment method, the material conductivity of the current blocking portion 190 farther from the set position is lower than the material conductivity of the current blocking portion 190 closer to the set position. By varying the material, the overall resistance of the corresponding light-emitting unit 110 can be adjusted. In specific applications, the three resistance adjustment methods described above can be used individually or simultaneously. Of course, the resistance adjustment methods are not limited to the examples described above.

[0049] In some optional embodiments, except for the light-emitting units 110 in the light-emitting area close to the set position, the other light-emitting units 110 are all provided with the current blocking part 190, that is, the light-emitting unit 110 closest to the set position may not be provided with the current blocking part 190.

[0050] Specifically, if Figures 1 to 4 As shown, the light emitting area includes a first light emitting area and a second light emitting area. The first light emitting area is closer to the center of the light emitting unit area 101 relative to the second light emitting area. The second light emitting area is set at the periphery of the first light emitting area (as shown in FIG. Figure 3 As shown); or, the second light-emitting area is arranged on a side of the first light-emitting area away from the set position. In specific applications, the first light-emitting area can be circular or polygonal, and the second light-emitting area can be annular or polygonal, and the second light-emitting area is arranged around the periphery of the first light-emitting area, that is, the light-emitting unit 110 in the second light-emitting area is closer to the edge of the vertical cavity surface emitting laser relative to the light-emitting unit 110 in the first light-emitting area. Of course, in specific applications, a third light-emitting area can also be provided around the second light-emitting area. Similarly, a fourth light-emitting area can also be provided around the third light-emitting area, and so on, which will not be repeated here.

[0051] Specifically, the current blocking portion 190 is provided under each light-emitting unit 110 in the first light-emitting area, and the total resistance value of the light-emitting unit 110 is R1. The current blocking portion 190 is provided under each light-emitting area, and the total resistance value of the light-emitting unit is R2, and R1 is smaller than R2. In this way, the light-emitting unit 110 that is relatively close to the set position (the center of the light-emitting unit area) has relatively larger current and power.

[0052] In this embodiment, one light-emitting unit 110 is provided in the first light-emitting area, and the light-emitting unit 110 is provided at the center point, or a plurality of light-emitting units 110 are provided in the first light-emitting area, and each of the light-emitting units 110 is evenly distributed along the circumferential direction with the center point as the center; that is, the first light-emitting area can be provided with one or more light-emitting units 110. In this embodiment, the light-emitting unit 110 in the first light-emitting area is taken as one as an example. Of course, the number of light-emitting units 110 in the first light-emitting area can also be three or four or other appropriate numbers. When the first light-emitting area is provided with a plurality of light-emitting units 110, each light-emitting unit 110 can be arranged according to a set rule or randomly arranged.

[0053] Specifically, a plurality of light-emitting units 110 are provided in the second light-emitting area. In this embodiment, six light-emitting units 110 are provided in the second light-emitting area as an example. Of course, the number of light-emitting units 110 can also be 8 or 10 or other appropriate numbers, and each of the light-emitting units 110 is evenly distributed around the periphery of the first light-emitting area along the circumferential direction with the center point as the center. Each light-emitting unit 110 can be arranged according to a set rule or randomly.

[0054] In specific applications, if more light-emitting units 110 or a larger vertical cavity surface emitting laser is required, the light-emitting area further includes a third light-emitting area, which can be arranged around the periphery of the second light-emitting area. The third light-emitting area is provided with a plurality of light-emitting units 110, and each of the light-emitting units 110 is evenly distributed around the periphery of the second light-emitting area along the circumferential direction with the center point as the center, forming a three-ring structure.

[0055] In specific applications, each light-emitting unit 110 can be arranged in a double-ring or multi-ring manner, wherein the inner ring can have one or more light-emitting units 110, and the second ring and the third ring can be provided with multiple light-emitting units 110. Among them, the (closer) light-emitting unit 110 to the outer ring has a larger corresponding resistance value (the resistance value is adjusted by the current blocking part 190), so as to reduce the current and power of the outer ring light-emitting unit 110 and prevent its light-emitting angle from being too large.

[0056] Specifically, if Figures 1 to 4As shown, each of the light-emitting units 110 includes a light-emitting hole 111 and a current injection structure, which can be arranged around the light-emitting hole 111; 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, and the first electrode 120 can be electrically connected to the first power supply input part 210, and 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 conductive channels 112 are provided around the periphery of each light-emitting hole 111. The conductive channels 112 can be (circular) cylindrical metal-filled holes. A plurality of conductive channels 112 can be correspondingly provided around the periphery of each light-emitting hole 111. Figure 2 In the embodiment, six conductive channels 112 are correspondingly provided on the periphery of each light-emitting hole 111 .

[0057] like Figure 3 and Figure 4 As shown, the VCSEL includes an ohmic contact layer 140, and the current blocking portion 190 is connected to the ohmic contact layer 140. One end of the conductive channel 112 is connected to the first electrode 120, and the ohmic contact layer 140 is a P-type ohmic contact layer connected to the other end of the conductive channel 112. A second electrode 170 (which can be a conductive metal layer for connection to the cathode) is provided on the bottom surface of the substrate 180. In a specific application, the epitaxial layer 160 includes, from top to bottom, a semiconductor contact layer 150, a P-DBR layer 161, an optoelectronic confinement layer (OA layer) 162, a multi-quantum well layer (MQW layer) 163, and an N-DBR layer 164. The P-DBR layer 161 is a P-type distributed Bragg reflector. Together with the bottom N-DBR layer 164, it forms an optical resonant cavity that reflects light of a specific wavelength and enhances laser output. The P-DBR layer 161 can be composed of alternating layers of materials with different refractive indices, typically with P-type doping. The optoelectronic confinement layer 162 (OA layer) serves to confine the light-emitting region of the vertical cavity surface emitting laser (VCSEL). This is primarily achieved by wet oxidation, where the high-aluminum layer in the P-DBR (P-DBR) is oxidized to aluminum oxide. This creates a refractive index difference with the high-aluminum layer in the central region, confining light. The aluminum oxide itself is insulating, thus enabling current control. The multi-quantum well layer 163 (MQW layer) serves as the active region, or MQW active region, where lasing occurs. The MQW structure consists of alternating well and barrier layers. Carriers (electrons and holes) recombine in the well layers, generating photons and achieving stimulated emission. The N-DBR layer 164 is an N-type distributed Bragg reflector (N-DBR). It serves as the bottom reflector and, together with the top P-DBR layer 161, forms an optical resonant cavity, reflecting light of a specific wavelength and enhancing laser output. The N-DBR layer 164 can be composed of alternating layers of materials with different refractive indices, typically N-type doped.

[0058] Specifically, the P-DBR layer 161 is located below the semiconductor contact layer 150 , and the P-DBR layer 161 , the photoelectric confinement layer 162 , the multi-quantum well layer 163 and the N-DBR layer 164 are arranged from top to bottom.

[0059] In specific applications, the ohmic contact layer 140 can be a P-type ohmic contact layer or an N-type ohmic contact layer, corresponding to a front-emitting or back-emitting vertical cavity surface emitting laser. In this embodiment, the ohmic contact layer 140 is a P-type ohmic contact layer, and the vertical cavity surface emitting laser emits light from the front. When the ohmic contact layer 140 is an N-type ohmic contact layer, the N-type ohmic contact layer is positioned relative to the conductive channel 112 and closer to the second electrode 170, and the vertical cavity surface emitting laser is a back-emitting vertical cavity surface emitting laser.

[0060] Specifically, the device substrate 100 also includes a passivation layer (which may be a SiN layer) 130, the conductive channel 112 passes through the passivation layer 130, the first electrode 120 (which may be a gold-plated layer) is arranged on one side of the passivation layer 130 and connected to the first end of the conductive channel 112, and the P-type ohmic contact layer is arranged on the other side of the passivation layer 130 and connected to the second end of the conductive channel 112.

[0061] Specifically, the ohmic contact layer 140 is a P-type ohmic contact layer, one side of which is in contact with the conductive path 112. The current blocking portion 190 is disposed on the other side of the P-type ohmic contact layer. The current blocking portion 190 is layered and has a hollow hole. The current blocking portion 190 can be annular, etc. The hollow hole is coaxially arranged with the light-emitting hole 111. The inner diameter of the hollow hole is larger than the aperture of the light-emitting hole 111. The aperture of the hollow hole relatively close to the set position is larger than the aperture of the hollow hole relatively far from the set position. The larger the inner diameter of the hollow hole, the easier it is for current to pass through the current blocking portion 190.

[0062] Specifically, the current blocking portion 190 is made of an insulating or semi-insulating material. In specific applications, the current blocking portion 190 can be formed by epitaxially adding a layer of insulating material (e.g., silicon oxide, silicon nitride, or aluminum oxide), or by oxidizing the semiconductor contact layer 150 (AlGaAs system) to form aluminum oxide. The current blocking portion 190 can be made of the same material as the photoelectric confinement layer 162.

[0063] Specifically, the semiconductor contact layer 150 is provided with an etching groove, the current blocking portion 190 is filled in the etching groove and connected to the ohmic contact layer 140 . In this embodiment, the current blocking portion 190 is located below the ohmic contact layer 140 (P-type ohmic contact layer).

[0064] An embodiment of the present invention further provides a method for manufacturing a vertical cavity surface emitting laser, which is used to manufacture the above-mentioned vertical cavity surface emitting laser, comprising:

[0065] When manufacturing the light-emitting units 110 of the vertical cavity surface emitting laser, a current blocking portion 190 embedded in the epitaxial layer 180 is provided below the ohmic contact layer 140 corresponding to some or all of the light-emitting units 110. The current blocking portion 190 is configured so that the current injected into the epitaxial layer 180 by at least one of the light-emitting units 110 via the ohmic contact layer 140 is different from the current injected into the epitaxial layer 160 by the remaining light-emitting units 110 via the ohmic contact layer 140. The current blocking portion 190 is provided corresponding to some or all of the light-emitting units 110 so that the overall resistance value of the light-emitting units 110 away from a set position is greater than the overall resistance value of the light-emitting units 110 relatively close to the set position. The set position is the center point of the light-emitting unit region 101, or the device substrate 100 is provided with a first power supply input portion 210 located on one side of the light-emitting unit region 101, and the set position is a position away from the first power supply input portion 210.

[0066] 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 areas, so that the light-emitting areas are arranged from a set position to a position away from the set position; by making the resistance values ​​of the current blocking parts 190 in different light-emitting areas different, by setting a current blocking part 190 with a larger resistance value at a position relatively far away from the set position, thereby reducing the overall resistance value of the light-emitting unit 110 in the central part of the light-emitting area, the resistance value corresponding to the light-emitting unit 110 at the central position is deliberately reduced.

[0067] If the resistance values ​​of the light-emitting units 110 in the vertical cavity surface emitting laser are consistent, due to factors such as the length of the current path, the current distribution of each light-emitting unit 110 is actually uneven during the current injection process, and the injection current is higher for the light-emitting holes 111 on the periphery of the vertical cavity surface emitting laser. The more peripheral the light-emitting unit 110 is, the higher the injection current it carries, and the larger the corresponding light-emitting angle, which affects the far-field divergence angle. When the vertical cavity surface emitting laser is operating stably, its injection current is constant. In this embodiment, by deliberately reducing the resistance value corresponding to the light-emitting unit 110 at the center position, the current can be concentrated relatively to the center of the light-emitting area, thereby achieving the purpose of adjusting the current injection uniformity of different light-emitting units 110 at different positions, thereby avoiding the phenomenon of premature high-order modes in the peripheral light-emitting holes due to uneven injection current. Of course, similar effects can also be achieved by increasing the number of conductive channels 112 around the light-emitting hole 111 at the center position of the device or increasing the width of the P ohmic contact layer.

[0068] like Figure 3 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 channel 112, it passes through the ohmic contact layer 140, the hollow holes of the current blocking part 190, and the semiconductor contact layer 150, and then flows from the holes in the photoelectric confinement layer 162 to the multi-quantum well layer 163 to achieve laser excitation.

[0069] An embodiment of the present invention further provides a laser device, which includes the above-mentioned vertical cavity surface emitting laser.

[0070] An embodiment of the present invention further provides a light source for a laser radar system, comprising at least one of the above-mentioned vertical cavity surface emitting lasers.

[0071] An embodiment of the present invention further provides a laser radar system, comprising a transmitting component and a receiving component, wherein the transmitting component adopts the above-mentioned light source for the laser radar system.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A vertical cavity surface emitting laser, characterized in that: The device comprises a device base, wherein the device base comprises a substrate and a plurality of light-emitting units arranged on the substrate, wherein the light-emitting units are separated by grooves; The device substrate has a light-emitting unit area, the light-emitting unit area includes at least two light-emitting areas arranged from a set position to a position away from the set position, each light-emitting area is provided with at least one light-emitting unit; the set position is the center point of the light-emitting unit area, or the device substrate is provided with a first power supply input portion located on one side of the light-emitting unit area, and the set position is a position away from the first power supply input portion; Each light-emitting unit includes an epitaxial layer and an ohmic contact layer sequentially arranged on the substrate; the groove is opened in the epitaxial layer; a current blocking portion embedded in the epitaxial layer is provided under the ohmic contact layer corresponding to some or all of the light-emitting units; the current blocking portion is configured to control the current injected into the epitaxial layer by at least one of the light-emitting units through the ohmic contact layer to be different from the current injected into the epitaxial layer by the remaining light-emitting units through the ohmic contact layer, so that the overall resistance value of the light-emitting unit far away from the set position is greater than the overall resistance value of the light-emitting unit relatively close to the set position.

2. A vertical cavity surface emitting laser according to claim 1, characterized in that: The thickness of the current blocking portion relatively far from the set position is greater than the thickness of the current blocking portion relatively close to the set position; Alternatively, the width of the current blocking portion relatively far from the set position is greater than the width of the current blocking portion relatively close to the set position; Alternatively, the material conductivity of the current blocking portion relatively far from the set position is lower than the material conductivity of the current blocking portion relatively close to the set position.

3. The vertical cavity surface emitting laser according to claim 1, wherein: Except for the light-emitting units in the light-emitting area close to the set position, the other light-emitting units are all provided with the current blocking portion.

4. The vertical cavity surface emitting laser according to claim 1, wherein: The light-emitting area includes a first light-emitting area and a second light-emitting area, the first light-emitting area is closer to the center of the light-emitting unit area than the second light-emitting area, and the second light-emitting area is arranged on the periphery of the first light-emitting area, or the second light-emitting area is arranged on a side of the first light-emitting area away from the set position; The current blocking portion is provided under each light-emitting unit in the first light-emitting area, and the total resistance value of the light-emitting unit is R1. The current blocking portion is provided under each light-emitting unit in the second light-emitting area, and the total resistance value of the light-emitting unit is R2, and R1 is smaller than R2.

5. A vertical cavity surface emitting laser according to any one of claims 1 to 4, characterized in that: Each of the light-emitting units includes a light-emitting hole and a current injection structure arranged around the light-emitting hole; a first electrode is provided on one side of the device substrate, and a second electrode is provided 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 the periphery of each light-emitting hole; The current blocking portion is in contact with the ohmic contact layer; One end of the conductive channel is connected to the first electrode, and the ohmic contact layer is a P-type ohmic contact layer connected to the other end of the conductive channel.

6. The vertical cavity surface emitting laser according to claim 5, characterized in that: One side of the P-type ohmic contact layer is connected to the conductive channel, and the current blocking portion is arranged on the other side of the P-type ohmic contact layer. The current blocking portion is layered and has a hollow hole, and the hollow hole is coaxially arranged with the light-emitting hole.

7. The vertical cavity surface emitting laser according to claim 6, wherein: The inner diameter of the hollow hole is larger than the aperture of the light-emitting hole, and the aperture of the hollow hole relatively close to the set position is larger than the aperture of the hollow hole relatively far from the set position.

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

9. The vertical cavity surface emitting laser according to claim 8, wherein: The current blocking portion is made of insulating material or semi-insulating material; Alternatively, the semiconductor contact layer is provided with an etching groove, and the current blocking portion is filled in the etching groove and is in contact with the ohmic contact layer.

10. A method for preparing a vertical cavity surface emitting laser, characterized in that: Used to manufacture a vertical cavity surface emitting laser according to any one of claims 1 to 9, comprising: When the light-emitting units of the vertical cavity surface emitting laser are manufactured, a current blocking portion embedded in the epitaxial layer is provided below the ohmic contact layer corresponding to some or all of the light-emitting units; the current blocking portion is configured so that the current injected into the epitaxial layer via the ohmic contact layer by at least one of the light-emitting units is different from the current injected into the epitaxial layer via the ohmic contact layer by the remaining light-emitting units, so that the overall resistance value of the light-emitting unit far away from the set position is greater than the overall resistance value of the light-emitting unit relatively close to the set position.

11. A light source for a laser radar system, characterized in that: The method comprises at least one vertical cavity surface emitting laser according to any one of claims 1 to 9.

12. A laser radar system, characterized in that: It comprises a transmitting component for transmitting a light source and a receiving component for receiving a light source, wherein the transmitting component adopts the light source for a laser radar system as claimed in claim 11.

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