Vertical cavity surface-emitting laser and lidar

Abstract

This application relates to a vertical-cavity surface-emitting laser (VCSEL) and a lidar. The VCSEL includes a substrate and light-emitting units. Multiple light-emitting units are arranged in an array on the substrate along the X-axis and Y-axis to form a light-emitting array. The light-emitting array includes multiple light-emitting rows and multiple light-emitting columns. Each light-emitting row has multiple light-emitting units arranged along the X-axis, and the multiple light-emitting rows are arranged along the Y-axis. Each light-emitting column has multiple light-emitting units arranged along the Y-axis, and the multiple light-emitting columns are arranged along the X-axis. The multiple light-emitting units in the light-emitting rows are arranged in a serpentine pattern along the X-axis and / or the multiple light-emitting units in the light-emitting columns are arranged in a serpentine pattern along the Y-axis. This arrangement allows for a denser arrangement of multiple light-emitting units while maintaining a small spacing between adjacent light-emitting rows and / or light-emitting columns. This results in a VCSEL with a high power density while achieving both high power and miniaturization.

Description

Technical Field

[0001] This application relates to the field of laser technology, and in particular to a vertical cavity surface-emitting laser and a lidar. Background Technology

[0002] Currently, vertical cavity surface emitting lasers (VCSELs) are an important type of semiconductor laser, widely used in optical communication, sensing, and consumer electronics due to their advantages such as small size, circular output spot, low threshold current, high-frequency modulation, and large-scale array integration.

[0003] To increase the power of conventional VCSEL lasers, the usual approach is to increase the size of the substrate to arrange more light-emitting units on the substrate. However, this leads to a larger VCSEL laser size. How to balance high power and miniaturization in VCSEL lasers is a problem that urgently needs to be solved. Utility Model Content

[0004] Therefore, it is necessary to provide a vertical-cavity surface-emitting laser that can balance high power and miniaturization. Furthermore, this application also protects a lidar having the aforementioned vertical-cavity surface-emitting laser.

[0005] A vertical-cavity surface-emitting laser, comprising: Substrate; and A light-emitting unit, wherein a plurality of light-emitting units are arranged in an array along the X-axis and Y-axis directions on the substrate to form a light-emitting array; the light-emitting array includes a plurality of light-emitting rows and a plurality of light-emitting columns, wherein the light-emitting rows have a plurality of light-emitting units arranged along the X-axis direction, the plurality of light-emitting rows are arranged along the Y-axis direction, the plurality of light-emitting columns have a plurality of light-emitting units arranged along the Y-axis direction, and the plurality of light-emitting columns are arranged along the X-axis direction; the plurality of light-emitting units in the light-emitting rows are arranged in a serpentine pattern along the X-axis direction and / or the plurality of light-emitting units in the light-emitting columns are arranged in a serpentine pattern along the Y-axis direction.

[0006] In the aforementioned vertical cavity surface-emitting laser, by arranging multiple light-emitting units in the light-emitting rows and / or columns of the light-emitting array in a serpentine pattern, the arrangement of multiple light-emitting units can be made more dense while keeping the spacing between adjacent light-emitting rows and / or columns small. This allows the vertical cavity surface-emitting laser to have a large power density while achieving both high power and miniaturization.

[0007] In one embodiment, the light-emitting rows and / or columns of the plurality of light-emitting units arranged in a serpentine pattern are defined as light-emitting groups. The distance between two adjacent light-emitting groups is P, and P≤2*OA, where OA is the pore size of the oxide hole of the light-emitting unit, and its unit is μm.

[0008] In one embodiment, the pore size OA of the oxide pore of the light-emitting unit is in the range of 5μm≤OA≤300μm.

[0009] In one embodiment, the light-emitting rows and / or columns of the plurality of light-emitting units arranged in a serpentine pattern are defined as light-emitting groups, one or more adjacent light-emitting groups are divided into a light-emitting region, the light-emitting array is divided into a plurality of light-emitting regions, and any two adjacent light-emitting regions are electrically isolated from each other.

[0010] In one embodiment, a trench for electrical isolation is formed between any two adjacent light-emitting regions.

[0011] In one embodiment, the trench is filled with a passivation layer.

[0012] In one embodiment, the vertical cavity surface emitter (VCSEL) includes a first pad and a second pad. There are multiple first pads, each electrically connected to one of the multiple light-emitting units. There are multiple second pads, each corresponding to one of the multiple light-emitting regions. In any light-emitting region, multiple first pads connected to multiple light-emitting units are electrically connected to the second pad corresponding to that light-emitting region.

[0013] In one embodiment, the first pad is connected to the side of the light-emitting unit away from the substrate, and the second pad is connected to the side of the first pad away from the substrate.

[0014] A lidar includes a transmitter and a receiver. The transmitter employs a vertical cavity surface emitter laser as described above and is used to emit laser signals. The receiver is used to receive the laser signals emitted by the transmitter.

[0015] In one embodiment, the light-emitting array of the vertical cavity surface emitter is divided into multiple light-emitting regions, and the receiving end has multiple detection regions, with the multiple light-emitting regions corresponding to the multiple detection regions.

[0016] In the aforementioned lidar, the use of a vertical cavity surface-emitting laser with a large power density improves the signal reception accuracy at the receiver and enhances the target detection capability of the lidar. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the arrangement of the light-emitting array in a vertical cavity surface-emitting laser according to an embodiment of this application; Figure 2 for Figure 1 A schematic diagram of the arrangement of another embodiment of the light-emitting array shown; Figure 3 for Figure 1 A schematic diagram of the arrangement of another embodiment of the light-emitting array shown; Figure 4 For along Figure 1 A schematic diagram of the structure of a vertical cavity surface-emitting laser (VCSEL) cut across the rear section with O as the center point, as indicated by the middle arrow. Explanation of reference numerals in the attached figures: 100, Vertical-cavity surface-emitting laser; 200, Substrate; 300, Light-emitting array; 310, Light-emitting unit; 320, Light-emitting row; 330, Light-emitting column; 340, Light-emitting group; 370, Light-emitting region; 350, Trench; 360, Passivation layer; 400, First pad; 500, Second pad. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0020] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0022] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0024] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0025] Combination Figures 1 to 4As shown, this application protects a vertical-cavity surface-emitting laser 100, which includes a substrate 200 and light-emitting units 310. Multiple light-emitting units 310 are arranged in an array on the substrate 200 along the X-axis and Y-axis directions to form a light-emitting array 300. The light-emitting array 300 includes multiple light-emitting rows 320 and multiple light-emitting columns 330. Each light-emitting row 320 has multiple light-emitting units 310 arranged along the X-axis, and the multiple light-emitting rows 320 are arranged along the Y-axis. Each light-emitting column 330 has multiple light-emitting units 310 arranged along the Y-axis, and the multiple light-emitting columns 330 are arranged along the X-axis. The multiple light-emitting units 310 in the light-emitting rows 320 are arranged in a serpentine pattern along the X-axis and / or the multiple light-emitting units 310 in the light-emitting columns 330 are arranged in a serpentine pattern along the Y-axis.

[0026] Understandable, Figure 1 In the light-emitting row 320, multiple light-emitting units 310 are arranged in a serpentine pattern along the X-axis, while multiple light-emitting units 310 in the light-emitting column 330 are arranged in a straight line along the Y-axis. Alternatively, in... Figure 2 In the illustrated embodiment, the plurality of light-emitting units 310 in the light-emitting row 320 can be arranged in a straight line along the X-axis direction, while the plurality of light-emitting units 310 in the light-emitting column 330 can be arranged in a serpentine pattern along the Y-axis direction. Alternatively, in... Figure 3 In the embodiment shown, the multiple light-emitting units 310 in the light-emitting row 320 can also be arranged in a serpentine pattern along the X-axis direction, while the multiple light-emitting units 310 in the light-emitting column 330 can also be arranged in a serpentine pattern along the Y-axis direction.

[0027] It should be noted that for the light-emitting row 320 or light-emitting column 330, the serpentine arrangement of its multiple light-emitting units 310 can be understood as follows: any two adjacent light-emitting units 310 are staggered in a direction perpendicular to the arrangement direction of the multiple light-emitting units 310, so that the light-emitting row 320 as a whole presents an approximately serpentine or wavy arrangement in the X-axis direction and the light-emitting column 330 as a whole presents an approximately serpentine or wavy arrangement in the Y-axis direction, and the line connecting two adjacent light-emitting units 310 will be inclined relative to both the X-axis and the Y-axis. This arrangement can make the arrangement of multiple light-emitting units 310 in the light-emitting array 300 more dense while keeping the spacing between two adjacent light-emitting rows 320 and two light-emitting columns 330 small. In this way, more light-emitting units 310 can be arranged on a smaller substrate 200, thereby improving the power density.

[0028] In the aforementioned vertical cavity surface-emitting laser 100, by arranging the multiple light-emitting units 310 in the light-emitting rows 320 and / or light-emitting columns 330 of the light-emitting array 300 in a serpentine pattern, this arrangement allows the multiple light-emitting units 310 to be arranged more densely while keeping the spacing between adjacent light-emitting rows 320 and / or light-emitting columns 330 small. This results in the vertical cavity surface-emitting laser 100 having a large power density while achieving both high power and miniaturization.

[0029] Continue reading Figures 1 to 4 In this application, a row 320 and / or column 330 of multiple light-emitting units 310 arranged in a serpentine pattern are defined as a light-emitting group 340. The distance between two adjacent light-emitting groups 340 is P, where P ≤ 2*OA, and OA is the aperture size of the oxide hole (not shown) of the light-emitting unit 310, in μm. It can be understood that when multiple light-emitting units 310 in a light-emitting group 340 are arranged in a serpentine pattern, it is a light-emitting row 320 when the multiple light-emitting units 310 are arranged in a serpentine pattern along the X-axis, and a light-emitting column 330 when the multiple light-emitting units 310 are arranged in a serpentine pattern along the Y-axis.

[0030] like Figure 1 As shown, multiple light-emitting units 310 in the light-emitting row 320 are arranged in a serpentine pattern to form a light-emitting group 340. Thus, multiple light-emitting rows 320 constitute multiple light-emitting groups 340. The multiple light-emitting rows 320 are evenly spaced along the Y-axis, so the distance between any two adjacent light-emitting rows 320 is P. For example... Figure 2 As shown, multiple light-emitting units 310 in the light-emitting column 330 are arranged in a serpentine pattern to form a light-emitting group 340. Thus, multiple light-emitting columns 330 constitute multiple light-emitting groups 340. The multiple light-emitting columns 330 are evenly spaced along the X-axis, so the distance between any two adjacent light-emitting columns 330 is P. For example... Figure 3 As shown, the multiple light-emitting units 310 in the light-emitting row 320 and light-emitting column 330 are arranged in a serpentine pattern, so that the light-emitting row 320 and light-emitting column 330 are both light-emitting groups 340. In the Y-axis direction, the multiple light-emitting rows 320 are evenly spaced and the distance between any two adjacent light-emitting rows 320 is P. In the X-axis direction, the multiple light-emitting columns 330 are evenly spaced and the distance between any two adjacent light-emitting columns 330 is P.

[0031] It can be understood that the distance between two adjacent light-emitting groups 340 is P, which is also the distance between the center points of the corresponding two light-emitting units 310 in two adjacent light-emitting groups 340.

[0032] Furthermore, the aperture OA of the oxide aperture in the light-emitting unit 310 is in the range of 5μm ≤ OA ≤ 300μm. It can be understood that the aperture OA of the oxide aperture in the light-emitting unit 310 can be any value between 5μm and 300μm. For example, when OA = 5μm, the distance P between two adjacent light-emitting groups 340 is ≤ 10μm; when OA = 10μm, the distance P between two adjacent light-emitting groups 340 is ≤ 20μm; when OA = 20μm, the distance P between two adjacent light-emitting groups 340 is ≤ 40μm; and when OA = 30μm, the distance P between two adjacent light-emitting groups 340 is ≤ 60μm. In this application, the vertical-cavity surface-emitting laser 100 frequently selects light-emitting units 310 with apertures between 10μm and 30μm.

[0033] In this application, for multiple light-emitting groups 340, one or more adjacent light-emitting groups 340 are divided into a light-emitting region 370, and the light-emitting array 300 is divided into multiple light-emitting regions 370, with electrical isolation between any two adjacent light-emitting regions 370. Specifically, as... Figure 1 As shown, a light-emitting row 320 (i.e., a light-emitting group 340) can be divided into a light-emitting region 370, thereby multiple light-emitting rows 320 (i.e., multiple light-emitting groups 340) constitute multiple light-emitting regions 370. Any two adjacent light-emitting regions 370 are electrically isolated. Alternatively, in other embodiments, two or three light-emitting rows 320 can be divided into a light-emitting region 370. For the resulting multiple light-emitting regions 370, adjacent two light-emitting regions 370 are also electrically isolated. Similarly, as... Figure 2 As shown, a light-emitting column 330 (i.e., a light-emitting group 340) can be divided into a light-emitting region 370, thereby multiple light-emitting columns 330 (i.e., multiple light-emitting groups 340) constitute multiple light-emitting regions 370. Any two adjacent light-emitting regions 370 are electrically isolated. Alternatively, in other embodiments, two or three light-emitting columns 330 can be divided into a light-emitting region 370. For the resulting multiple light-emitting regions 370, adjacent two light-emitting regions 370 are also electrically isolated. It should be noted that by dividing the light-emitting array 300 into multiple light-emitting regions 370 and electrically isolating adjacent light-emitting regions 370, it is convenient to realize the partitioned control of multiple light-emitting units 310.

[0034] Research has shown that when P=2*OA, there is no gap between two adjacent light-emitting regions 370 in the arrangement direction of multiple light-emitting groups 340, and the number and density of light-emitting units 310 that can be set on the surface of substrate 200 are relatively large. However, when P<2*OA, there is partial overlap between two adjacent light-emitting regions 370 in the arrangement direction of multiple light-emitting groups 340, which further increases the density of light-emitting units 310 that can be set on the surface of substrate 200.

[0035] Combination Figure 1 and Figure 4 As shown, a trench 350 for electrical isolation is further formed between any two adjacent light-emitting regions 370. By providing a trench 350 between the two light-emitting regions 370, electrical contact can be avoided. Specifically, a passivation layer 360 is filled in the trench 350. The passivation layer 360 is specifically an insulating material, which can prevent current leakage between different light-emitting regions 370, thereby improving the power conversion efficiency and allowing more electrical energy to be used to generate laser light.

[0036] like Figure 1 , Figure 4 As shown, a light-emitting row 320 (i.e., a light-emitting group 340) is divided into a light-emitting region 370, so that multiple light-emitting rows 320 (i.e., multiple light-emitting groups 340) constitute multiple light-emitting regions 370. A groove 350 can be provided between any two adjacent light-emitting regions 370. The groove 350 is serpentine and filled with a passivation layer 360.

[0037] Combination Figure 1 and Figure 4 As shown in the specific embodiment of this application, the vertical cavity surface-emitting laser 100 includes a first pad 400 and a second pad 500. There are multiple first pads 400, which are electrically connected to multiple light-emitting units 310 in a one-to-one correspondence. There are multiple second pads 500, which correspond to multiple light-emitting regions 370 in a one-to-one correspondence. In any light-emitting region 370, the multiple first pads 400 connected to the multiple light-emitting units 310 are electrically connected to the second pads 500 corresponding to the light-emitting region 370.

[0038] Specifically, the first pad 400 is electrically connected to the light-emitting unit 310 on the side of the light-emitting unit 310 away from the substrate 200, and the second pad 500 is electrically connected to multiple first pads 400 on the side of the first pad 400 away from the substrate 200. In this way, the first pads 400 and the second pads 500 are stacked in the Z-axis direction (i.e., the epitaxial direction), which is perpendicular to both the X-axis and the Y-axis. This allows for the corresponding control of multiple light-emitting units 310 through multiple first pads 400, and also enables unified control of each light-emitting unit 310 within the light-emitting area 370 corresponding to the second pad 500 through the second pad 500 and the first pads 400.

[0039] Furthermore, control of multiple light-emitting regions 370 can be achieved by setting more, for example, third pads (not shown) in the Z-axis direction to connect with multiple second pads 500. In this way, by arranging the light-emitting array 300 and dividing the light-emitting regions 370 in the plane defined by the X and Y axes, and with the electrical connection of multi-level pads, three-dimensional control and adjustment of multiple light-emitting units 310 can be achieved.

[0040] This application also protects a lidar. The lidar includes a transmitter and a receiver. The transmitter uses the aforementioned vertical cavity surface emitter laser 100 and is used to emit laser signals. The receiver is used to receive the laser signals emitted by the transmitter.

[0041] Specifically, the emitting array 300 of the vertical-cavity surface-emitting laser 100 is divided into multiple emitting regions 370, and the receiving end has multiple detection regions, with the multiple emitting regions 370 corresponding to the multiple detection regions. It can be understood that after the laser signal emitted by the transmitting end illuminates the target object, the laser signal is reflected by the target object and can be received by the receiving end. The receiving end has multiple detection regions, which correspond to the multiple emitting regions 370 of the transmitting end. This correspondence helps each detection region to more accurately receive the laser echo emitted by a specific emitting region 370, achieving the best sensing effect, thereby improving the accuracy and efficiency of signal reception. This facilitates subsequent processing and analysis of target information in different regions, and parameters such as the distance of the corresponding target object can be determined based on the laser reflection of different emitting regions 370. Furthermore, in lidar, because the vertical-cavity surface-emitting laser 100 has a large power density, the signal reception accuracy of the receiving end is also improved, thus enhancing the target detection sensitivity of the lidar.

[0042] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0043] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A vertical cavity surface emitting laser, characterized by, include: Substrate; and A light-emitting unit, wherein multiple light-emitting units are arranged in an array on the substrate along the X-axis and Y-axis directions to form a light-emitting array; The light-emitting array includes multiple light-emitting rows and multiple light-emitting columns. Each light-emitting row has multiple light-emitting units arranged along the X-axis direction. The multiple light-emitting rows are arranged along the Y-axis direction. Each light-emitting column has multiple light-emitting units arranged along the Y-axis direction. The multiple light-emitting columns are arranged along the X-axis direction. The multiple light-emitting units in the light-emitting rows are arranged in a serpentine pattern along the X-axis direction and / or the multiple light-emitting units in the light-emitting columns are arranged in a serpentine pattern along the Y-axis direction.

2. The vertical cavity surface emitting laser according to claim 1, characterized in that The light-emitting rows and / or columns of multiple light-emitting units arranged in a serpentine pattern are defined as light-emitting groups. The distance between two adjacent light-emitting groups is P, and P≤2*OA, where OA is the pore size of the oxide pore of the light-emitting unit, and its unit is μm.

3. The vertical cavity surface emitting laser according to claim 2, characterized in that The pore size OA of the oxide pores in the light-emitting unit is in the range of 5μm≤OA≤300μm.

4. The vertical cavity surface emitting laser of claim 2, wherein, One or more adjacent light-emitting groups are divided into a light-emitting region, the light-emitting array is divided into multiple light-emitting regions, and any two adjacent light-emitting regions are electrically isolated.

5. The vertical cavity surface emitting laser of claim 4, wherein, A trench for electrical isolation is formed between any two adjacent light-emitting regions.

6. The vertical cavity surface emitting laser of claim 5, wherein, The trench is filled with a passivation layer.

7. The vertical cavity surface emitting laser of claim 4, wherein, The vertical cavity surface emitter (VCSEL) includes a first pad and a second pad. There are multiple first pads, each electrically connected to one of the multiple light-emitting units. There are multiple second pads, each corresponding to one of the multiple light-emitting regions. In any light-emitting region, multiple first pads connected to multiple light-emitting units are electrically connected to the second pad corresponding to that light-emitting region.

8. The vertical cavity surface emitting laser of claim 7, wherein, The first pad is connected to the side of the light-emitting unit away from the substrate, and the second pad is connected to the side of the first pad away from the substrate.

9. A lidar, characterized in that, It includes a transmitter and a receiver. The transmitter is a vertical cavity surface emitter laser as described in any one of claims 1 to 8 and is used to emit laser signals. The receiver is used to receive the laser signals emitted by the transmitter.

10. The lidar of claim 9, wherein, The emitting array of the vertical cavity surface emitter laser is divided into multiple emitting regions, and the receiving end has multiple detection regions, with the multiple emitting regions corresponding to the multiple detection regions.

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