Semiconductor laser and laser radar

Abstract

The invention provides a semiconductor laser and a laser radar. The semiconductor laser plays a role in heat dissipation through a thermoelectric refrigeration device fixed on a light-emitting main body. The thermoelectric refrigeration device is composed of P-type thermoelectric elements and N-type thermoelectric elements which are alternately arranged in the current direction, and the P-type thermoelectric elements and the N-type thermoelectric elements are electrically connected through a conductive heat dissipation piece clamped between the P-type thermoelectric elements and the N-type thermoelectric elements, so that a thermocouple structure is formed. Compared with a traditional thermocouple structure, the thermocouple structure provided by the invention adopts a thermoelectric element with a smaller size, but can achieve the same heat dissipation effect. Through the improvement, more thermoelectric elements can be arranged in the same space, so that the heat dissipation density is remarkably improved. According to the laser radar, the innovative semiconductor laser is adopted as a transmitting assembly, and the thermocouple structure is optimized, so that the more efficient heat dissipation performance is realized, and the stability and durability of the laser are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a semiconductor laser and a laser radar. Background Art

[0002] Vertical-Cavity Surface-Emitting Laser (VCSEL) is an advanced semiconductor laser. Its uniqueness lies in the formation of a resonant cavity in the vertical direction of the substrate and the emission of laser in the vertical direction. VCSEL has significant advantages such as small temperature drift, low threshold, easy fiber coupling, low power consumption and good dynamic single-mode performance. It has shown great potential in application scenarios such as automotive laser radar, face recognition, and 3D sensing.

[0003] However, the working environment of VCSEL in automotive LiDAR is relatively harsh. When the working environment temperature reaches a certain level, the optical power of VCSEL will drop rapidly. This is because the performance of VCSEL deteriorates with the increase of temperature, and its thermal sensitivity makes it difficult to maintain the best working state in a high temperature environment.

[0004] In order to reduce the operating temperature of VCSEL and maintain its optimal performance, the current mainstream cooling method is to mount a semiconductor cooler (TEC) on the bottom of the chip. However, as the size of VCSEL chips continues to shrink and the application scenarios become more diverse, it is of great significance to improve the heat dissipation effect within a limited size to promote the further development and application of VCSEL technology. Summary of the invention

[0005] The purpose of this application is to provide a semiconductor laser and a laser radar that can improve the above-mentioned problems.

[0006] The embodiment of the present application is implemented as follows: In a first aspect, the present application provides a semiconductor laser, comprising: a light-emitting body and a thermoelectric cooling device provided on a non-light-emitting side of the light-emitting body, wherein the thermoelectric cooling device is configured to dissipate heat from the light-emitting body; The thermoelectric cooling device includes P-type thermoelectric elements and N-type thermoelectric elements alternately arranged along the current direction of the thermoelectric cooling device, and the adjacent P-type thermoelectric elements and N-type thermoelectric elements are electrically connected through a conductive heat sink sandwiched between the two to form a thermocouple structure.

[0007] It can be understood that the present application provides a semiconductor laser, which plays a role in heat dissipation through a thermoelectric cooling device arranged on the light-emitting body. The thermoelectric cooling device is composed of P-type thermoelectric elements and N-type thermoelectric elements arranged alternately along the current direction, and are electrically connected by a conductive heat sink sandwiched between the two, thereby forming a thermocouple structure. Compared with the traditional thermocouple structure, the thermocouple structure in the present application uses smaller-sized thermoelectric elements, but can achieve the same heat dissipation effect. This improvement allows more thermoelectric elements to be arranged in the same space, thereby significantly improving the heat dissipation density. Therefore, the thermoelectric cooling device structure disclosed in the present application not only optimizes the heat dissipation performance of the semiconductor laser, but also provides new possibilities for the miniaturization and high efficiency of the semiconductor laser by increasing the integration of the thermoelectric elements.

[0008] In an optional embodiment of the present application, the conductive heat sink is arranged as follows: At least one of the conductive heat sinks extends toward the light-emitting body to form a first heat sink; At least one of the conductive heat sinks extends in a direction away from the light-emitting body to form a second heat sink; Two adjacent conductive heat sinks extend in different directions.

[0009] It can be understood that the conductive heat sink can extend outward in addition to the area in contact with the thermoelectric element. Whether it extends toward the light-emitting body or extends in a direction away from the light-emitting body, the heat dissipation area of ​​the conductive heat sink can be increased, thereby achieving a better heat dissipation effect. In addition, the extension of two adjacent conductive heat sinks in different directions can avoid the extension parts of the two adjacent conductive heat sinks being restricted to each other on the same side and blocking each other's extension size. The scheme of extending the upper and lower layers separately can make more full use of space and achieve the effect of maximizing the extension area.

[0010] In an optional embodiment of the present application, the surface of the conductive heat sink facing the adjacent P-type thermoelectric element is the first surface, and the surface of the conductive heat sink facing the adjacent N-type thermoelectric element is the second surface; the conductive heat sink whose current direction is from the first surface to the second surface is a PN-type conductive heat sink, and the conductive heat sink whose current direction is from the second surface to the first surface is an NP-type conductive heat sink; and / or each of the PN-type conductive heat sinks extends toward the light-emitting body to form the first heat sink; and each of the NP-type conductive heat sinks extends in a direction away from the light-emitting body to form the second heat sink.

[0011] In an optional embodiment of the present application, insulating materials are filled between adjacent conductive heat sinks, between the conductive heat sink and the P-type thermoelectric element, and between the conductive heat sink and the N-type thermoelectric element. It can be understood that the filling of insulating materials avoids poor conduction of various elements in the thermoelectric cooling device, ensuring that the thermoelectric cooling device does not have a short circuit failure and maintains normal operation.

[0012] In an optional embodiment of the present application, the thermoelectric cooling device also includes a first protective plate and a second protective plate; the insulating material is an insulating glue with adhesion, the first protective plate is covered on the first side of each of the thermocouple structures through the insulating glue, and the second protective plate is covered on the second side of each of the thermocouple structures through the insulating glue, and the first side is opposite to the second side.

[0013] It can be understood that the insulating material uses an insulating glue with adhesiveness, which, on the one hand, prevents the poor conduction between the various components in the thermoelectric cooling device, and on the other hand, two protective plates can be added on the upper and lower sides of the thermoelectric cooling device. The protective plate can, on the one hand, play a certain packaging and protection role for each thermocouple structure, and on the other hand, can be fixed to the light-emitting body by gold-gold bonding, thereby enhancing the stability of the combination between the thermoelectric cooling device and the light-emitting body.

[0014] In an optional embodiment of the present application, the first protection plate and the light-emitting body are fixed by gold-gold bonding; and / or the second protection plate and the light-emitting body are fixed by gold-gold bonding.

[0015] In an optional embodiment of the present application, the semiconductor laser includes at least one of the following: A first electrode is disposed on a first surface of the conductive heat sink facing the adjacent P-type thermoelectric element, and the first electrode is soldered to the P-type thermoelectric element by solder; A second electrode is disposed on a second surface of the conductive heat sink facing the adjacent N-type thermoelectric element, and the second electrode is soldered to the N-type thermoelectric element by soldering.

[0016] In an optional embodiment of the present application, a dimension of the conductive heat sink along the current direction is a thickness of the conductive heat sink, and the thickness of the conductive heat sink is less than a preset threshold.

[0017] It can be understood that in a conventional thermocouple structure, the size of the P-type thermoelectric element and the N-type thermoelectric element is the same, and the thickness of the conductive heat sink is generally set to be smaller, that is, smaller than the side length of the cross section of the thermoelectric element perpendicular to the current direction, so that the thermocouple structure provided by the present application can further ensure that the heat dissipation effect achieved by the large-sized thermoelectric element in the conventional thermocouple structure is achieved by using a smaller-sized thermoelectric element. That is, the above-mentioned preset threshold can be set to the minimum value of the side length of the above-mentioned cross section.

[0018] In an optional embodiment of the present application, the light-emitting body is a VCSEL chip, including a substrate layer, a first-type doped semiconductor layer, an active layer, and a second-type doped semiconductor layer stacked in sequence; a first chip electrode is arranged on the first-type doped semiconductor layer, and a second chip electrode is arranged on the second-type doped semiconductor layer. It can be understood that the vertical cavity surface emitting laser (VCSEL) chip starts with a substrate layer, on which are sequentially a first-type doped semiconductor layer (such as an N-type doped semiconductor layer), an active layer, and a second-type doped semiconductor layer (such as a P-type doped semiconductor layer), forming a PN junction. When the carriers of the P region and the N region are injected into the active layer under the action of an external circuit, the electrons and holes recombine in the active layer, releasing energy and generating photons. Since the cavity of the VCSEL is vertical, the photons are reflected multiple times between the reflectors formed by the two layers of doped semiconductor layers and are stimulated and amplified to form coherent light. Finally, these photons are vertically emitted from the top of the chip to form a laser beam. The first electrode and the second electrode are disposed on the first-type doped semiconductor layer and the second-type doped semiconductor layer, respectively, and are configured to apply a voltage to drive the injection of carriers and stimulate photon emission.

[0019] In an optional embodiment of the present application, the substrate layer is fixed to the thermoelectric cooling device by gold-gold bonding. In combination with the above, the substrate layer can be fixed to the first protective plate or the second protective plate by gold-gold bonding. Gold-gold bonding forms a high-strength metallurgical bond through direct diffusion and bonding between metal atoms. This bonding method can withstand greater mechanical and thermal stresses, ensuring the reliability and stability of the connection.

[0020] In a second aspect, the present application provides a laser radar, comprising a transmitting component and a receiving component; the transmitting component adopts a semiconductor laser as described in any one of the above-mentioned first aspects.

[0021] It is understandable that this type of LiDAR uses an innovative semiconductor laser as the transmitting component, and achieves more efficient heat dissipation performance by optimizing the thermocouple structure, improving the stability and durability of the laser. Its miniaturization and high-efficiency design provide solid technical support for the wide application of LiDAR in harsh environments such as vehicle-mounted and face recognition.

[0022] Beneficial effects:

[0023] The present application provides a semiconductor laser, which plays a role in heat dissipation through a thermoelectric cooling device fixed on the light-emitting body. The thermoelectric cooling device is composed of P-type thermoelectric elements and N-type thermoelectric elements arranged alternately along the current direction, and electrically connected by a conductive heat sink sandwiched between the two, thereby forming a thermocouple structure. Compared with the traditional thermocouple structure, the thermocouple structure in the present application uses smaller-sized thermoelectric elements, but can achieve the same heat dissipation effect. This improvement allows more thermoelectric elements to be arranged in the same space, thereby significantly improving the heat dissipation density. Therefore, the thermoelectric cooling device structure disclosed in the present application not only optimizes the heat dissipation performance of the semiconductor laser, but also provides new possibilities for the miniaturization and high efficiency of the semiconductor laser by increasing the integration of the thermoelectric elements.

[0024] In order to make the above-mentioned objects, features and advantages of the present application more obvious and understandable, optional embodiments are specifically listed below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a schematic diagram of the structure of a semiconductor laser provided by the present application; Figure 2 yes Figure 1 A schematic diagram of a single thermocouple structure in a thermoelectric cooling device shown; Figure 3 It is a schematic diagram of the structure of a traditional thermocouple; Figure 4 It is a schematic diagram of the structure of another semiconductor laser provided in this application. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] like Figure 1The figure is a schematic structural diagram of a semiconductor laser 100 provided by the present application. The semiconductor laser 100 includes: a light-emitting body 10 and a thermoelectric cooling device 20 fixed on the light-emitting body 10 . The thermoelectric cooling device 20 is configured to dissipate heat for the light-emitting body 10 .

[0029] The thermoelectric cooling device 20 includes a current direction (eg Figure 1 The P-type thermoelectric elements 21 and the N-type thermoelectric elements 22 are alternately arranged (as shown by the dotted arrows in FIG. 1 ), and the adjacent P-type thermoelectric elements 21 and N-type thermoelectric elements 22 are electrically connected by a conductive heat sink 23 sandwiched therebetween to form a thermocouple structure.

[0030] The above-mentioned alternating arrangement means that the thermoelectric element combinations of the same structure are arranged in sequence in the current direction of the thermoelectric cooling device, and in these thermoelectric element combinations, the arrangement form of the P-type thermoelectric element and the N-type thermoelectric element is the same. That is, along the current direction of the thermoelectric cooling device, the P-type thermoelectric element is arranged first, and then the N-type thermoelectric element is arranged; or, along the current direction of the thermoelectric cooling device, the N-type thermoelectric element is arranged first, and then the P-type thermoelectric element is arranged.

[0031] The above-mentioned clamping means that the conductive heat sink is arranged between the P-type thermoelectric element and the N-type thermoelectric element. Specifically, the first surface of the conductive heat sink facing the adjacent P-type thermoelectric element is physically connected to the P-type thermoelectric element and electrically connected; the second surface of the conductive heat sink facing the adjacent N-type thermoelectric element is physically connected to the N-type thermoelectric element and electrically connected.

[0032] Optionally, the conductive heat sink 23 may be made of copper or aluminum with good thermal conductivity and good electrical conductivity, so as to facilitate the attachment of thermoelectric materials and the flow of current at low resistance. The thermoelectric material may be manganese silicide compounds (Mn-Si), magnesium silicide compounds (Mg-Si-Sn), cobaltite compounds (Co-Sb), half-Heusler compounds (Zr-Ni-Sn) and bismuth telluride compounds (Bi-Te). Figure 2 yes Figure 1 Schematic diagram of a single thermocouple structure in a thermoelectric cooling device shown in FIG. In the thermocouple structure, adjacent P-type thermoelectric elements 21 and N-type thermoelectric elements 22 are electrically connected via a conductive heat sink 23 disposed in the middle. Figure 2 For the thermocouple structure shown, when it is at the best cooling thermal power, the resistance of the conductive heat sink satisfies the following formula: ,in, represents the resistance of the conductive heat sink, i.e. the parasitic resistance, represents the thickness of the conductive heat sink, Represents the length value of P-type thermoelectric element and N-type thermoelectric element, Represents the width value of P-type thermoelectric element, N-type thermoelectric element, and conductive heat sink. Represents the thickness of P-type thermoelectric element and N-type thermoelectric element, Represents the resistivity of the conductive heat sink. When it is at its optimal cooling thermal power, the resistance of the P-type / N-type thermoelectric element satisfies the following formula: ,in, Represents the resistance of the P-type / N-type thermoelectric element, represents the resistivity of the P-type / N-type thermoelectric element. Therefore, Figure 2 The ratio of parasitic resistance to the resistance loss of the thermoelectric element in the thermocouple structure shown Satisfy the following formula: .

[0033] In a conventional thermocouple structure, adjacent P-type thermoelectric elements and N-type thermoelectric elements are electrically connected via a conductive heat sink covering the top surface. Figure 3 300 is a schematic diagram of the structure of a conventional thermocouple structure, wherein a P-type thermoelectric element 301 and an N-type thermoelectric element 302 are electrically connected via a first conductive heat sink 303 covering the top surface, a P-type thermoelectric element 301 and another N-type thermoelectric element located on the left (not shown in the figure) are electrically connected via a second conductive heat sink 304 covering the bottom surface, and an N-type thermoelectric element 302 and another P-type thermoelectric element located on the right (not shown in the figure) are electrically connected via a third conductive heat sink 305 covering the bottom surface. Figure 3 For the traditional thermocouple structure shown in the figure, when it is at the best cooling thermal power, the resistance of the conductive heat sink satisfies the following formula: ,in, represents the resistance of the conductive heat sink, i.e. the parasitic resistance, Represents the distance between the P-type thermoelectric element and the N-type thermoelectric element, Represents the length of the overlapped area between the P-type thermoelectric element or the N-type thermoelectric element and the conductive heat sink. Represents the width value of P-type thermoelectric element, N-type thermoelectric element, and conductive heat sink. represents the thickness of the conductive heat sink, Represents the thickness of P-type thermoelectric element and N-type thermoelectric element, Represents the resistivity of the conductive heat sink. When it is at its optimal cooling thermal power, the resistance of the P-type / N-type thermoelectric element satisfies the following formula: ,in, Represents the resistance of the P-type / N-type thermoelectric element, represents the resistivity of the P-type / N-type thermoelectric element. Therefore, Figure 3 The ratio of parasitic resistance to the resistance loss of the thermoelectric element in the thermocouple structure shown Satisfy the following formula: .

[0034] exist Figure 2 and Figure 3 When the material parameters of the P-type thermoelectric element, N-type thermoelectric element, and conductive heat sink are consistent, the same resistance loss ratio should be maintained, that is, , the thickness of the thermoelectric element needs to meet the following conditions: Generally speaking, Figure 3 In , The value will be The value is designed to be larger, while limiting Figure 2 In The value is less than the preset threshold, that is, less than value, in satisfying Under the conditions, .for Figure 2 and Figure 3 The thermocouple structures shown can all achieve the same optimal cooling thermal power, which requires the following equation to be satisfied: ,because ,therefore , then it is understandable, Figure 2 The volume of the thermoelectric element in the thermocouple structure shown will be less than Figure 3 The volume of the thermoelectric element in the traditional thermocouple structure shown ,Right now .

[0035] It can be seen that the use of Figure 2 With the thermocouple structure, the smaller thermoelectric element can achieve the heat dissipation effect achieved by the large-sized thermoelectric element in the traditional thermocouple structure. Figure 2 The thermocouple structure can arrange more thermoelectric elements in the same space, thereby improving the heat dissipation density.

[0036] It can be understood that the thermocouple structure in the present application uses a smaller-sized thermoelectric element, but can achieve the same heat dissipation effect. This improvement allows more thermoelectric elements to be arranged in the same space, thereby significantly improving the heat dissipation density. Therefore, the thermoelectric cooling device 20 structure disclosed in the present application not only optimizes the heat dissipation performance of the semiconductor laser 100, but also provides new possibilities for miniaturization and high efficiency of the semiconductor laser 100 by improving the integration of thermoelectric elements.

[0037] In an optional embodiment of the present application, the dimension of the conductive heat sink 23 along the current direction is the thickness of the conductive heat sink 23, and the thickness of the conductive heat sink 23 is less than a preset threshold. It can be understood that in a conventional thermocouple structure, the dimensions of the P-type thermoelectric element 21 and the N-type thermoelectric element 22 are the same, and the thickness of the conductive heat sink 23 is generally set to be smaller, that is, smaller than the side length of the cross section of the thermoelectric element perpendicular to the current direction. This can further ensure that the thermocouple structure provided by the present application can achieve the heat dissipation effect achieved by the large-sized thermoelectric elements in the traditional thermocouple structure with smaller-sized thermoelectric elements. That is, the above-mentioned preset threshold can be set to the minimum value of the above-mentioned cross-sectional side length, such as Figure 2 As shown, the above preset threshold can be set to be less than value.

[0038] like Figure 1 As shown in the enlarged view in FIG, a first chip electrode 24 is arranged on the first surface of the conductive heat sink 23 facing the adjacent P-type thermoelectric element 21, and the first chip electrode 24 is soldered to the P-type thermoelectric element 21 by solder; a second chip electrode 25 is arranged on the second surface of the conductive heat sink 23 facing the adjacent N-type thermoelectric element 22, and the second chip electrode 25 is soldered to the N-type thermoelectric element 22 by solder.

[0039] Continue to refer Figure 1 As shown, the light-emitting body 10 is a VCSEL chip, including a substrate layer 11, a first-type doped semiconductor layer 12, an active layer 13 and a second-type doped semiconductor layer 14 stacked in sequence; a first chip electrode 15 is arranged on the first-type doped semiconductor layer 12, and a second chip electrode 16 is arranged on the second-type doped semiconductor layer 14. It can be understood that the vertical cavity surface emitting laser (VCSEL) chip starts with a substrate layer 11, on which are sequentially a first-type doped semiconductor layer 12 (such as an N-type doped semiconductor layer), an active layer 13 and a second-type doped semiconductor layer 14 (such as a P-type doped semiconductor layer), forming a PN junction. When the carriers of the P region and the N region are injected into the active layer 13 under the action of an external circuit, the electrons and holes recombine in the active layer 13, releasing energy and generating photons. Since the cavity of the VCSEL is vertical, the photons are reflected multiple times between the reflectors formed by the two layers of doped semiconductor layers and are stimulated and amplified to form coherent light. Finally, these photons are emitted vertically from the top of the chip to form a laser beam. The first chip electrode 24 and the second chip electrode 25 are respectively disposed on the first type doped semiconductor layer 12 and the second type doped semiconductor layer 14, and are configured to apply voltage to drive the injection of carriers and stimulate photon emission.

[0040] Optionally, the light-emitting body 10 further includes a confinement ring 17, which is disposed on a side of the active layer 13 close to the first-type doped semiconductor layer 12 or on a side of the active layer 13 close to the second-type doped semiconductor layer 14. After the light-emitting body 10 is turned on, the current is restricted by the confinement ring 17, and is finally introduced into the light-emitting area of ​​the light-emitting body 10, so that the light-emitting area of ​​the light-emitting body 10 generates laser. More specifically, in the embodiment of the present application, the confinement ring 17 has a confinement area surrounding the light-emitting area, the confinement area has a higher resistivity to restrict the flow of carriers into the middle area of ​​the light-emitting body 10, and the refractive index of the confinement area is lower to laterally confine photons, and the carrier and optical lateral confinement increases the density of carriers and photons in the active layer 13, thereby improving the efficiency of generating light in the active layer 13. The confinement ring 17 can be implemented as an oxidized confinement layer, which is formed on the upper side and / or lower side of the active layer 13 by an oxidation process. The confinement ring 17 may also be implemented in other types, for example, implemented as an ion confinement layer formed on the upper side or the lower side of the active layer 13 by an ion implantation process.

[0041] In an optional embodiment of the present application, the substrate layer 11 is fixed to the thermoelectric cooling device 20 by gold-gold bonding. Figure 1 The gold-gold bonding layer 18 connects the substrate layer 11 and the thermoelectric cooling device 20. Gold-gold bonding forms a high-strength metallurgical bond through direct diffusion and bonding between metal atoms. This bonding method can withstand greater mechanical and thermal stresses, and enhances the bonding stability between the thermoelectric cooling device and the light-emitting body.

[0042] In an optional embodiment of the present application, the semiconductor laser includes at least one of the following: At least one conductive heat sink extends toward the light-emitting body to form a first heat sink; At least one conductive heat sink extends in a direction away from the light-emitting body to form a second heat sink; Two adjacent conductive heat sinks extend in different directions.

[0043] It can be understood that the conductive heat sink can extend outward in addition to the area in contact with the thermoelectric element. Whether it extends toward the light-emitting body or extends in a direction away from the light-emitting body, the heat dissipation area of ​​the conductive heat sink can be increased, thereby achieving a better heat dissipation effect. In addition, the extension of two adjacent conductive heat sinks in different directions can avoid the extension parts of the two adjacent conductive heat sinks being restricted on the same side and blocking each other's extension size. The scheme of extending the upper and lower layers separately can make more full use of space and achieve the effect of maximizing the extension area.

[0044] like Figure 4 Shown is a schematic structural diagram of another semiconductor laser 200 provided in the present application. Figure 4 The light emitting body 30 and Figure 1 The structure of the light emitting body 10 shown is the same, but Figure 4 Thermoelectric cooling device 40 and Figure 1 The thermoelectric cooling device 20 in FIG. 1 is slightly different. Figure 4 As shown, the thermoelectric cooling device 40 includes a current direction along the thermoelectric cooling device 40 (such as Figure 4 The P-type thermoelectric elements 41 and the N-type thermoelectric elements 42 are arranged alternately (as shown by the dotted arrows in FIG. 1 ), and the adjacent P-type thermoelectric elements 41 and N-type thermoelectric elements 42 are electrically connected through a conductive heat sink sandwiched between the two to form a thermocouple structure. Figure 1 Unlike the thermoelectric cooling device 20 in the embodiment, the conductive heat sinks in the thermoelectric cooling device 40 are divided into two types, namely, PN-type conductive heat sinks 43 and NP-type conductive heat sinks 44. Each PN-type conductive heat sink 43 extends from between the P-type thermoelectric element 41 and the N-type thermoelectric element 42 toward the light-emitting body 10 to form a first heat sink 430; each NP-type conductive heat sink 44 extends from between the P-type thermoelectric element 41 and the N-type thermoelectric element 42 in a direction away from the light-emitting body 10 to form a second heat sink 440.

[0045] For example, taking the N-type thermoelectric element 42 as an example, it may include a first end and a second end that are arranged opposite to each other, and there is a temperature difference between the first end and the second end; the NP-type conductive heat sink 44 is configured to perform heat exchange with the first end of the N-type thermoelectric element 42, and the PN-type conductive heat sink 43 is configured to perform heat exchange with the second end of the N-type thermoelectric element 42; further, the DC current passing from the N-type thermoelectric element 42 to the P-type thermoelectric element 41 will cool the NP-type conductive heat sink 44 sandwiched between them, and the DC current passing from the P-type thermoelectric element 41 to the N-type thermoelectric element 42 will heat the PN-type conductive heat sink 43 sandwiched between them. Figure 4 As shown, insulating material 45 is filled between adjacent conductive heat sinks 43, between the conductive heat sink 43 and the P-type thermoelectric element 41, and between the conductive heat sink 43 and the N-type thermoelectric element 42. It can be understood that the filling of the insulating material avoids the poor conduction of each element in the thermoelectric cooling device 40, ensuring that the thermoelectric cooling device 40 does not have a short circuit fault and maintains normal operation.

[0046] like Figure 4As shown, the thermoelectric cooling device 40 also includes a first protective plate 46 and a second protective plate 47; the insulating material 45 is an insulating glue with adhesive properties, the first protective plate 46 is covered on the first side of each thermocouple structure by the insulating glue, and the second protective plate 47 is covered on the second side of each thermocouple structure by the insulating glue, and the first side is opposite to the second side. It can be understood that the insulating material uses an insulating glue with adhesive properties, which, on the one hand, prevents poor conduction between the various components in the thermoelectric cooling device, and on the other hand, two protective plates can be added on the upper and lower sides of the thermoelectric cooling device. On the one hand, the protective plate can play a certain packaging and protection role for each thermocouple structure, and on the other hand, it can also be fixed to the light-emitting body by gold-gold bonding, thereby enhancing the bonding stability between the thermoelectric cooling device and the light-emitting body.

[0047] In an optional embodiment of the present application, the first protection plate 46 is fixed to the light-emitting body 10 by gold-gold bonding; or, the second protection plate 47 is fixed to the light-emitting body 10 by gold-gold bonding.

[0048] In combination with the above, the first protective plate 46 or the second protective plate 47 can be fixed to the substrate layer 11 by gold-gold bonding. Gold-gold bonding forms a high-strength metallurgical bond through direct diffusion and bonding between metal atoms. This bonding method can withstand greater mechanical and thermal stresses, ensuring the reliability and stability of the connection. Figure 4 The gold-gold bonding layer 48 connects the light-emitting body 30 and the first protection plate 46 .

[0049] The substrate layer, the first protective plate, and the second protective plate are all non-metallic materials. Fixing them by gold-gold bonding actually means first plating a layer of metal (such as gold, silver, etc.) on the surface of these non-metallic materials, and then bonding through the metal layer. The specific bonding steps include: first, plating a uniform metal layer on the substrate layer and the bonding surface of the first protective plate / second protective plate; cleaning the surface plated with the metal layer to remove surface pollutants, oxides, etc. to ensure the purity and flatness of the bonding surface; placing the treated parts in a vacuum or inert gas environment for preheating to remove residual moisture and gas on the surface and improve the activity of the metal surface; at a predetermined temperature and vacuum degree, aligning and closely contacting the substrate layer with the first protective plate / second protective plate, applying a certain pressure and maintaining a certain temperature, so that the two metal layers diffuse and combine with each other at the atomic scale; gradually reducing the temperature and pressure to cool and solidify the bonding interface to form a stable bonding structure; finally, inspecting and testing the bonded semiconductor laser to ensure that the bonding quality and device performance meet the design requirements.

[0050] The present application also provides a laser radar, including a transmitting component and a receiving component; the transmitting component adopts a semiconductor laser as described in any of the above items. This laser radar adopts an innovative semiconductor laser as a transmitting component, and achieves more efficient heat dissipation performance by optimizing the thermocouple structure, thereby improving the stability and durability of the laser. Its miniaturized and high-efficiency design provides solid technical support for the wide application of laser radar in harsh environments such as vehicle-mounted and face recognition.

[0051] The expressions "first", "second", "the first" or "the second" used in various embodiments of the present disclosure may modify various components regardless of order and / or importance, but these expressions do not limit the corresponding components. The above expressions are only configured for the purpose of distinguishing an element from other elements. For example, a first user device and a second user device represent different user devices, although both are user devices. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the present disclosure.

[0052] When one element (e.g., a first element) is referred to as being "(operably or communicatively) coupled" or "(operably or communicatively) coupled to" or "connected to" another element (e.g., a second element), it is understood that the one element is directly connected to the other element or the one element is indirectly connected to the other element via yet another element (e.g., a third element). Conversely, it is understood that when an element (e.g., a first element) is referred to as being "directly connected" or "directly coupled" to another element (the second element), no element (e.g., a third element) is interposed between the two.

[0053] It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0054] The above description is only an optional embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above invention concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

[0055] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0056] The above description is only an optional embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above invention concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

[0057] The above is only an optional embodiment of the present application and is not configured to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A semiconductor laser, characterized in that: include: A light-emitting body and a thermoelectric cooling device provided on a non-light-emitting side of the light-emitting body, wherein the thermoelectric cooling device is configured to dissipate heat from the light-emitting body; The thermoelectric cooling device includes P-type thermoelectric elements and N-type thermoelectric elements alternately arranged along the current direction of the thermoelectric cooling device, The adjacent P-type thermoelectric elements and the adjacent N-type thermoelectric elements are electrically connected via a conductive heat sink sandwiched between the two to form a thermocouple structure.

2. The semiconductor laser according to claim 1, characterized in that The conductive heat sink is arranged as follows: At least one of the conductive heat sinks extends toward the light-emitting body to form a first heat sink; At least one of the conductive heat sinks extends in a direction away from the light-emitting body to form a second heat sink; Two adjacent conductive heat sinks extend in different directions.

3. The semiconductor laser according to claim 2, characterized in that The surface of the conductive heat sink facing the adjacent P-type thermoelectric element is a first surface, and the surface of the conductive heat sink facing the adjacent N-type thermoelectric element is a second surface; The conductive heat sink whose current direction is from the first surface to the second surface is a PN type conductive heat sink, and the conductive heat sink whose current direction is from the second surface to the first surface is an NP type conductive heat sink; and / or Each of the PN-type conductive heat sinks extends toward the light-emitting body to form the first heat sink; each of the NP-type conductive heat sinks extends in a direction away from the light-emitting body to form the second heat sink.

4. The semiconductor laser according to claim 2, characterized in that Insulating materials are filled between adjacent conductive heat sinks, between the conductive heat sink and the P-type thermoelectric element, and between the conductive heat sink and the N-type thermoelectric element.

5. The semiconductor laser according to claim 4, characterized in that The thermoelectric cooling device also includes a first protective plate and a second protective plate; the insulating material is an insulating glue with adhesiveness, the first protective plate is covered on the first side of each of the thermocouple structures through the insulating glue, and the second protective plate is covered on the second side of each of the thermocouple structures through the insulating glue, and the first side is opposite to the second side.

6. The semiconductor laser according to claim 5, characterized in that The first protection plate is fixed to the light-emitting body by gold-gold bonding; and / or, The second protection plate is fixed to the light-emitting body by gold-gold bonding.

7. The semiconductor laser according to any one of claims 1 to 6, characterized in that: Include at least one of the following: A first electrode is disposed on a first surface of the conductive heat sink facing the adjacent P-type thermoelectric element, and the first electrode is soldered to the P-type thermoelectric element by solder; A second electrode is disposed on a second surface of the conductive heat sink facing the adjacent N-type thermoelectric element, and the second electrode is soldered to the N-type thermoelectric element by soldering.

8. The semiconductor laser according to any one of claims 1 to 6, characterized in that: The size of the P-type thermoelectric element is the same as the size of the N-type thermoelectric element; The dimension of the conductive heat sink along the current direction is the thickness of the conductive heat sink, and the thickness of the conductive heat sink is less than a preset threshold.

9. The semiconductor laser according to any one of claims 1 to 6, characterized in that: The light-emitting body is a VCSEL chip, which includes a substrate layer, a first-type doped semiconductor layer, an active layer and a second-type doped semiconductor layer stacked in sequence; a first chip electrode is arranged on the first-type doped semiconductor layer, and a second chip electrode is arranged on the second-type doped semiconductor layer.

10. A laser radar, characterized in that: It comprises a transmitting component and a receiving component; the transmitting component adopts the semiconductor laser as described in any one of claims 1-9.

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