A semiconductor laser based on multi-stage step dense packaging

Abstract

The application discloses a semiconductor laser based on multi-stage step dense packaging, which comprises a heat sink provided with a bottom surface and a top surface arranged in parallel and oppositely, a first step array connected to the bottom surface and a second step array connected to the top surface, and the first step array and the second step array are installed in a forward and inverted complementary mode. The first step array and the second step array each comprise a plurality of step surfaces arranged in an array along a first direction and a second direction, and the distance of the corresponding step surfaces on each step array from the bottom surface decreases from large to small along the first direction and the second direction. The step surfaces on one step array are provided with laser modules, and the step surfaces on the other step array are provided with optical assemblies, and the number of the laser modules and the optical assemblies is equal and one-to-one corresponding. The first step array and the second step array of the scheme are installed in a forward and inverted complementary mode, the idle space above the step array can be effectively utilized, and the overall size of the semiconductor laser is significantly reduced.

Description

Technical Field

[0001] This application relates to the technical field of space optimization for semiconductor lasers, and more particularly to a semiconductor laser based on multi-level step-dense packaging. Background Technology

[0002] Semiconductor lasers are widely used due to their advantages such as small size, high electro-optical conversion efficiency and long life. In high-power scenarios, multiple COS components need to be integrated and matched with FAC and SAC components to complete beam collimation.

[0003] Currently, in existing traditional packaging structures, different columns of optical components require SAC components with different focal lengths, which not only increases the costs of lens procurement, warehousing and assembly, but also leads to deviations in the size of each group of laser spots, significantly increasing the difficulty of subsequent beam shaping.

[0004] Meanwhile, traditional heat sinks have low integration density and large device spacing, making it impossible to pack more COS components within a limited volume, thus limiting the improvement of power density. In addition, the heat generated by the operation of multiple components is prone to accumulate, causing problems such as chip wavelength drift and reduced electro-optic efficiency, further shortening the device lifespan. Summary of the Invention

[0005] The purpose of this invention is to provide a semiconductor laser based on multi-level step-dense packaging, which can solve the above-mentioned problems existing in the prior art.

[0006] To achieve the above objectives, this application adopts the following technical solution: On the one hand, a semiconductor laser based on multi-level step-dense packaging is provided, comprising: A heat sink has a bottom surface and a top surface that are parallel and opposite to each other. A first stepped array is connected to the bottom surface and a second stepped array is connected to the top surface. The first stepped array and the second stepped array are installed in a complementary manner, with the first and second stepped arrays being upright and inverted. Both the first and second stepped arrays include multiple stepped surfaces arranged in an array along the first and second directions, and the distance between the corresponding stepped surface on each stepped array and the bottom surface decreases from large to small along the first and second directions. In one of the stepped arrays, a laser module is installed on the stepped surface, and an optical component is installed on the stepped surface of the other stepped array. The number of laser modules and optical components are equal and they correspond one-to-one.

[0007] Preferably, along the first direction and the second direction, the step surface on the first step array can be defined as Txy, and the step surface on the second step array can be defined as Sxy, where x and y are positive integers greater than 0; Wherein, the step surfaces with the same subscript in the first step array and the second step array have a mapping relationship, the mapping relationship including: Two stepped surfaces with a mapping relationship have a preset first offset in the first direction and a preset second offset in a third direction perpendicular to the bottom surface; and the stepped surfaces with the same subscripts in the first stepped array and the second stepped array are respectively used to connect the laser module and the optical component with a corresponding relationship.

[0008] Preferably, the first direction and the second direction are perpendicular to each other.

[0009] Preferably, along the first direction, the height difference between adjacent step surfaces is a first fixed value; and Along the second direction, the height difference between adjacent step surfaces is a second fixed value.

[0010] Preferably, the laser module includes a COS component, and the heating surface of the COS component is in contact with the corresponding stepped surface it is mounted on.

[0011] Preferably, the optical element includes: The FAC component, correspondingly disposed at the laser emitting end of each of the COS components, is used for fast-axis collimation of the laser; and The SAC component, mounted on the stepped surface of another stepped array corresponding to the COS component, is used for slow-axis collimation of the laser beam emitted by the corresponding COS component.

[0012] Preferably, the optical element further includes a mirror assembly, which is mounted on the same step surface as the SAC assembly, for adjusting the beam direction of the laser beam collimated by the SAC assembly.

[0013] Preferably, the heat sink has a light-emitting window, which is located on the optical path of the laser beam after it has been adjusted by the reflector assembly.

[0014] Preferably, the heat sink is provided with a heat dissipation structure, which is located on one side of the laser module and is used for heat exchange with the laser module.

[0015] Preferably, an electrode is also fixed on the heat sink, the inner side of the electrode is electrically connected to each of the laser modules, and the outer side of the electrode is used for connecting an external power supply.

[0016] The beneficial effects of this application are as follows: By setting up a first-tier and second-tier arrays arranged opposite each other on the heat sink and adopting a complementary forward and inverted mounting method, the unused space diagonally above the tiered arrays is effectively utilized, significantly reducing the horizontal width occupied by the optical path unit. Under the condition of the same number of light-emitting units, the overall size of the heat sink is significantly reduced, and the module weight is lowered, making the semiconductor laser suitable for handheld devices, UAV-borne laser systems, and space-constrained industrial processing scenarios, thus expanding its lightweight and high-power application range.

[0017] By designing a stepped surface height that decreases synchronously along the first and second directions, all stepped surfaces are spatially distributed with equal gradients, ensuring that the optical path transmission distance between each COS component installed on the corresponding stepped surface and the corresponding SAC component is completely consistent. Based on this equal optical path distance, all SAC components can use the same focal length specification, eliminating the need to configure slow-axis collimating lenses with different focal lengths for different columns or layers, thereby significantly reducing the types of materials used.

[0018] Since all optical paths have equal transmission distances and the SAC components use a uniform focal length specification, each beam has a consistent spot size and divergence angle after slow-axis collimation, eliminating the problems of inconsistent spot size and beam quality caused by focal length differences in traditional structures.

[0019] While ensuring consistent optical performance and output beam quality, it can effectively solve the prominent problems in existing technologies such as numerous SAC component specifications, poor beam consistency, insufficient integration, and limited heat dissipation, demonstrating significant technological advancement and broad industrial application prospects. Attached Figure Description

[0020] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the structure of a semiconductor laser based on multi-level step dense packaging according to an embodiment of this application; Figure 2 This is a schematic diagram of the bottom view of a semiconductor laser based on multi-level stepped dense packaging according to an embodiment of this application; Figure 3 This is a schematic diagram of the step surface layout and mapping relationship on the first and second step arrays of a semiconductor laser based on multi-level step dense packaging according to an embodiment of this application. Figure 4 This is a cross-sectional structural schematic diagram of a semiconductor laser based on multi-level step dense packaging according to an embodiment of this application; Figure 5This is a schematic diagram of the structure of the first and second stepped arrays of a semiconductor laser based on multi-level stepped dense packaging according to an embodiment of this application, viewed from a second direction. Figure 6 This is a schematic diagram of the structure of a first-step array of a semiconductor laser based on multi-step dense packaging according to an embodiment of this application; Figure 7 This is a schematic diagram of the heat dissipation structure of the first-step array of a semiconductor laser based on multi-step dense packaging, according to an embodiment of this application.

[0022] Figure 8 This is a schematic diagram of the simulated optical path structure of a semiconductor laser based on multi-level step-dense packaging in an embodiment of this application, showing two rows of stepped surfaces. Figure 9 This is a schematic diagram of the distribution structure of the laser module and optical components in a semiconductor laser based on multi-level step-dense packaging according to an embodiment of this application, in the state of multiple rows of step surfaces.

[0023] In the picture: 100. Heat sink; 110. Bottom surface; 1101. First opening; 120. Top surface; 1201. Second opening; 210. First-order ladder array; 220. Second-order ladder array; 300. COS components; 410. FAC assembly; 420. SAC assembly; 430. Mirror assembly; 500. Light-emitting window; 600. Heat dissipation structure; 610. Heat dissipation fins; 620. Cooling flow channel; 700, Electrode; DX, first direction; DY, second direction; DZ, third direction; Dh, preset offset; Dh1, first fixed value; Dh2, second fixed value. Detailed Implementation

[0024] To make the technical problems solved by this application, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this application are further described in detail below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] Semiconductor lasers, due to their small size, light weight, long lifespan, and high efficiency, are widely used in many fields such as solid-state laser pumping, laser processing, medical aesthetics, materials processing, and night vision illumination. However, the output power of a single semiconductor laser chip is relatively low. To obtain high-power laser output, techniques such as spatial beam combining, polarization beam combining, or wavelength beam combining are typically used to combine the lasers from multiple chips. Spatial beam combining technology uses reflection or refraction to superimpose multiple light spots in space. The more light-emitting units involved in beam combining, the higher the required system integration.

[0028] As market demand for the output power of semiconductor laser modules continues to increase, the number of chips integrated into a single module is also increasing, leading to a corresponding increase in the module's size and weight. This hinders the widespread application of semiconductor lasers in lightweight, high-power applications such as handheld devices, UAV-borne laser systems, and space-constrained industrial processing scenarios.

[0029] To address the shortcomings of existing SAC components, such as multiple specifications, high cost, poor beam uniformity, low device integration, and poor heat dissipation, this invention provides a semiconductor laser based on multi-level stepped dense packaging. By setting a combination structure of multi-level gradient steps on the heat sink 100, it achieves high-density arrangement of optical components, unifies the distance of each group of optical paths, and is compatible with single-specification SAC component 420; at the same time, it enhances the overall heat dissipation capacity and improves the laser output stability and service life.

[0030] Specifically, please refer to Figures 1 to 9This invention provides a semiconductor laser based on multi-level stepped dense packaging, comprising a heat sink 100 and a laser module and optical components disposed within the heat sink 100. The laser module is used to emit laser light, and the emitted laser light is shaped by the optical components. The heat sink 100 is manufactured using a one-piece machining process, and its overall shape is a block structure, the size of which can be flexibly adjusted according to the application scenario.

[0031] Furthermore, the heat sink 100 has a hollowed-out center with a base fixedly connected to it, and the base and heat sink 100 are integrally formed. The integral forming process ensures that there are no splicing gaps between the base and the heat sink 100, guaranteeing the continuity and integrity of the heat conduction path, eliminating contact interfaces and contact thermal resistance, and ensuring that heat can be efficiently conducted from the base to the heat sink 100.

[0032] The heat sink 100 has a parallel and opposite bottom surface 110 and top surface 120, which are formed on the base. Together, they form a cavity structure for mounting laser modules and optical components.

[0033] Within the cavity structure between the bottom surface 110 and the top surface 120, two sets of stepped arrays are provided, defined as the first stepped array 210 and the second stepped array 220, respectively. The first stepped array 210 is connected to one side of the bottom surface 110, and the second stepped array 220 is connected to one side of the top surface 120, with the first stepped array 210 and the second stepped array 220 positioned opposite each other. Specifically, the heat sink 100 is divided into left and right sections along its centerline, with the first stepped array 210 positioned on the left and the second stepped array 220 positioned on the right. The first stepped array 210 and the second stepped array 220 are not necessarily entirely located on the left or right side; they can also span the middle area, as long as they are positioned opposite each other.

[0034] The first stepped array 210 and the second stepped array 220 are installed in a complementary manner, with the first stepped array 210 and the second stepped array 220 being upright and inverted, respectively. That is, the first stepped array 210 and the second stepped array 220 can achieve spatial complementarity in the first direction DX and the second direction DY.

[0035] Preferably, the first stepped array 210 and the second stepped array 220 are integrally formed on the base to improve heat conduction efficiency.

[0036] The first step array 210 and the second step array 220 both include multiple step surfaces that are arrayed along the first direction DX and the second direction DY. The distance between the step surface on each step array and the bottom surface 110 is gradually decreasing along the first direction DX and the second direction DY.

[0037] The first direction DX is defined as the transverse direction of the heat sink 100 from left to right, and the second direction DY is defined as the longitudinal direction of the heat sink 100 along the bottom surface 110 or the top surface 120. The first direction DX and the second direction DY are perpendicular to each other. Viewed from a positive angle along the second direction DY, the first stepped array 210 is directly connected to the bottom surface 110, and the second stepped array 220 is inverted on the top surface 120. "Directly connected" means that the normal to the step surface of the first stepped array 210 is vertically upward, and the normal to the step surface of the second stepped array 220 is vertically downward.

[0038] In this embodiment, the number of stepped surfaces on the two stepped arrays is equal and they correspond one-to-one. Based on the first direction DX and the second direction DY, the stepped surface on the first stepped array 210 is defined as Txy, and the stepped surface on the second stepped array 220 is defined as Sxy, where x and y are positive integers. Specifically, for the stepped surface in the i-th column and j-th row, they are defined as Tij and Sij, and Tij and Sij correspond to each other.

[0039] Wherein, the step surfaces with the same subscript in the first step array 210 and the second step array 220 have a mapping relationship, the mapping relationship includes: the two step surfaces with the mapping relationship have a preset first offset in the first direction DX; and have a preset second offset in the third direction DZ perpendicular to the bottom surface 110.

[0040] Furthermore, the first direction DX and the second direction DY are perpendicular to each other, and the step surfaces with the same subscript in the first step array 210 and the second step array 220 are respectively used to connect the corresponding laser modules and optical components.

[0041] For example, step surface Tij corresponds to step surface Sij, representing the spatial mapping relationship between the two step surfaces. In this scheme, the mapping relationship includes at least the following: along the first direction DX, the distance between step surface Tij and step surface Sij is the same, and this distance is the first offset in the first direction DX.

[0042] Please see Figure 4 The first offset can be a preset offset Dh, which can be determined according to actual needs. By adjusting the size of this offset, the width of the heat sink 100 in the first direction DX can be controlled.

[0043] Alternatively, the mapping relationship may also include a preset second offset in a third direction DZ perpendicular to the bottom surface 110. This second offset allows for a certain height difference between the two corresponding stepped surfaces in the height direction, facilitating the installation of the laser module and the optical module. By setting a specific height difference, the optical path from the laser module to the optical module can be ensured to be smooth and stable. Since the second stepped array 220 and the first stepped array 210 are arranged complementaryly, the second stepped array 220 can effectively utilize the space area diagonally above the first stepped array 210, thereby optimizing the spatial layout of the heat sink 100 and effectively reducing the external dimensions of the semiconductor laser based on multi-step dense packaging.

[0044] Furthermore, in the two stepped arrays, laser modules are mounted on the stepped surfaces of one array, while optical components are correspondingly mounted on the stepped surfaces of the other array, with the number of laser modules and optical components being equal and in a one-to-one correspondence. This spatial arrangement of the two stepped arrays and the corresponding step surfaces allow beams at different heights to share the same optical path space, thus providing a hardware foundation for the subsequent use of a standardized SAC component 420. This alignment method ensures a clear and consistent relative positional relationship between the optical path units, facilitating standardized assembly and quality control.

[0045] This invention, through a step height design that decreases synchronously at each level, ensures that all optical paths have equal transmission distances, thereby unifying the focal length specifications of the SAC component 420. This not only reduces material costs but also eliminates the problem of spot size differences caused by SAC components 420 with different focal lengths, providing a uniform light source for subsequent beam combining.

[0046] In one embodiment, along the first direction DX, the height difference between adjacent step surfaces is a first fixed value Dh1; along the second direction DY, the height difference between adjacent step surfaces is a second fixed value Dh2. The first fixed value Dh1 and the second fixed value Dh2 may be the same or different.

[0047] By limiting the height difference between adjacent step surfaces along the first direction DX and the second direction DY, the internal structure of the semiconductor laser based on multi-level step-dense packaging can be effectively ensured to be coordinated and unified, and all laser modules and optical components can use the same model. For example, the height difference between two adjacent step surfaces is uniformly set to 1.8mm, and the transition position of the step surface is rounded (rounded corner R0.5mm) to avoid sharp edges scratching optical components.

[0048] Meanwhile, by setting the height difference between the stepped surfaces, it can be ensured that optical devices or laser modules installed on the same pair of stepped surfaces have their own independent height positions in the vertical direction, without interfering with each other. The relative height relationship between optical devices in the same pairing number in different columns is completely consistent, thereby ensuring that each group of optical path units has the same geometric configuration and guaranteeing the consistency of the optical performance of each optical path unit.

[0049] In one embodiment, the laser module includes a COS component 300, and the heating surface of the COS component 300 is in contact with its corresponding mounted stepped surface. The heat generated by the COS component 300 during operation can be transferred to the heat sink 100 via the stepped surface. The COS component 300 is the core device for laser emission. The stepped surface can avoid the upper optical path, and the vertical spacing between COS components 300 at different heights is only equal to the difference in step height. This arrangement allows for a denser beam arrangement within the same range of step height variation.

[0050] In one embodiment, the optical components include a FAC component 410 and a SAC component 420. The FAC component 410 is disposed correspondingly at the laser emitting end of each COS component 300 and is used for fast-axis collimation of the laser; the SAC component 420 is mounted on the stepped surface of another stepped array corresponding to the COS component 300 and is used for slow-axis collimation of the laser beam emitted by the corresponding COS component 300.

[0051] Specifically, the FAC component 410 is a fast-axis collimating lens, which is set one-to-one with the laser emitting end of each COS component 300 and arranged close to the light-emitting surface. It is used to collimate the laser emitted by the COS component 300 with the fast axis, converting the diverging beam in the fast axis direction into parallel light. After fast-axis collimation, the beam divergence angle is ≤2mrad.

[0052] The SAC module 420 is a slow-axis collimating lens, and all lenses use the same focal length, completely abandoning the traditional multi-focal-length mixed-use mode. The SAC module 420 is used to perform slow-axis collimation on lasers that have undergone fast-axis collimation, resulting in a beam divergence angle ≤1.5mrad after slow-axis collimation.

[0053] In existing technologies, because the distances from different COS components 300 to their corresponding SAC components 420 are unequal, SACs with different focal lengths must be used for each component. This increases the variety of materials and inventory costs. Furthermore, SACs with different focal lengths have different collimation effects on the beam, resulting in inconsistent beam spot sizes after collimation. Consequently, subsequent spatial or polarization beam combining is inefficient and produces poor beam quality. In this solution, however, the optical path transmission distance from each COS group to its corresponding SAC is equal, and all SAC components 420 can use the same focal length. SACs with uniform focal lengths produce consistent collimation effects on all beams, resulting in consistent beam spot sizes and divergence angles after collimation, providing a high-quality "raw beam" for subsequent beam combining.

[0054] In one embodiment, the optical assembly further includes a reflector assembly 430, which is mounted on the same stepped surface as the SAC assembly 420 and is used to adjust the direction of the laser beam collimated by the SAC assembly 420. The reflector assembly 430 uses a high-reflectivity dielectric film lens with a reflectivity ≥99.5%. The laser beam collimated by the slow axis of the SAC assembly 420 is incident on the reflector assembly 430, reflected, and then directed outwards.

[0055] In the actual optical propagation path, the laser emitted by the COS component 300 first undergoes fast-axis collimation via the FAC component 410. Based on the multi-stage densely packaged semiconductor laser, the fast-axis divergence angle is relatively large (typically 30°–60°), and the FAC component 410 compresses the beam in the fast-axis direction into quasi-parallel light. The beam after fast-axis collimation then enters the SAC component 420 for slow-axis collimation, where the divergence angle is relatively small (typically 5°–15°), and the SAC component 420 further collimates it into parallel light. Since all SACs have the same focal length, the spot size and beam quality of all beams after slow-axis collimation are consistent. The collimated parallel beams are reflected by the mirror component 430, changing their propagation direction before exiting uniformly, achieving spatial beam combining.

[0056] In one embodiment, a light-emitting window 500 is provided on the heat sink 100, and the light-emitting window 500 is located in the optical path of the laser beam adjusted by the reflector assembly 430. Specifically, the light-emitting window 500 is opened on the side wall of the heat sink 100 and is a rectangular through hole. Its opening direction is consistent with the second direction DY to ensure that the reflected laser can smoothly exit the heat sink 100.

[0057] In one embodiment, a heat dissipation structure 600 is provided on the heat sink 100. The heat dissipation structure 600 is disposed below the laser module and is used for heat exchange with the laser module. The heat dissipation structure 600 includes two forms, which can be selected according to the cooling method: an integrally formed heat dissipation fin 610, or a cooling channel 620 formed in the heat sink 100.

[0058] Specifically, the integrally formed heat dissipation fins 610 and heat sink 100 are integrally milled and distributed on the bottom and sides of heat sink 100. The surface of the heat dissipation fins 610 is brushed to increase the contact area with air and adapt to natural air cooling and forced air cooling conditions.

[0059] The cooling channel 620, located inside the heat sink 100, is a closed channel located directly below the step surface of the first stepped structure. The channel inlet and outlet are equipped with standard hydraulic joints, and circulating cooling water is introduced to achieve forced heat dissipation, making it suitable for ultra-high power lasers.

[0060] Heat can be directly transferred from the stepped surface to the heat dissipation structure 600 without obstruction of the heat conduction path. The heat dissipation structure 600 is positioned directly below the laser module, precisely targeting the heat source for heat dissipation, resulting in strong heat dissipation targeting. It should be noted that the heat dissipation structure 600 of this invention is not limited to the above-described form, and can be selected and determined according to actual needs.

[0061] In one embodiment, an electrode 700 is also fixed on the heat sink 100. The inner side of the electrode 700 is electrically connected to each laser module, and the outer side is used for connecting an external power supply. The electrode 700 is fixedly connected to the side wall of the heat sink 100 and is made of gold-plated copper, which has excellent conductivity and strong oxidation resistance, effectively improving the reliability of the electrode 700. The electrode 700 is divided into two groups, positive and negative electrodes, which are fixed to the side of the heat sink 100 by an insulating bracket and are electrically insulated from the heat sink 100 substrate.

[0062] Specifically, the inner side of electrode 700 is electrically connected to all COS components 300 via wires, using a parallel wiring method to ensure that the power supply voltage and current of each group of COS components 300 are completely consistent; terminals are led out from the outer side of electrode 700 for connecting to an external power supply for the laser. The wires are made of high-temperature resistant enameled wire, with a temperature resistance of ≥180℃, to adapt to the high-temperature operating environment of the laser.

[0063] Electrode 700 is integrated on heat sink 100, eliminating the need for additional electrode 700 support or lead frame, which reduces the number of components and assembly steps, thus helping to lower costs and reduce size. The short electrical connection path and low resistance between the inner side of electrode 700 and each COS component 300 reduce Joule heat loss during power transmission and improve overall electro-optical conversion efficiency. At the same time, the integrated design of electrode 700 and heat sink 100 makes the electrical connection of the entire device more reliable, effectively reducing the risk of poor contact caused by vibration or thermal cycling and improving the long-term reliability of the product.

[0064] In one embodiment, in the vertical direction, the heat sink 100 has a first opening 1101 on its bottom surface 110, corresponding to the second stepped array 220; the heat sink 100 has a second opening 1201 on its top surface 120, corresponding to the first stepped array 210. By providing openings on the bottom surface 110 and the top surface 120, it is convenient to install the laser module on the first stepped array 210 and the optical components on the second stepped array 220.

[0065] Specifically, the first opening 1101 and the second opening 1201 are milled onto the heat sink 100 and both are connected to the cavity between the bottom surface 110 and the top surface 120. Viewed from a forward angle along the second direction DY, the first opening 1101 and the second opening 1201 are spaced apart along the first direction DX. A cover plate is also detachably connected to the heat sink 100, located at the first opening 1101 and the second opening 1201, for sealing the first opening 1101 and the second opening 1201.

[0066] In one embodiment, the heat sink 100 is integrally manufactured from a high thermal conductivity metal or alloy material, and the optional materials include pure copper, aluminum alloy, diamond / copper composite material, etc.

[0067] The three types of materials are suitable for lasers of different power levels: Pure copper has a thermal conductivity of 401 W / (m·K), is tough, and has excellent processing performance, making it suitable for medium-to-high power lasers with continuous output power of 50W to 200W. Aluminum alloy has a thermal conductivity of 237 W / (m·K), is lightweight and inexpensive, making it suitable for medium-to-low power lasers with continuous output power <50W, and applicable to small civilian laser equipment. Diamond / copper composite material has a thermal conductivity of 600 to 800 W / (m·K), has the best thermal conductivity, and its coefficient of thermal expansion matches the laser chip well, making it suitable for ultra-high power lasers with continuous output power >200W and industrial-grade high-power laser equipment.

[0068] The high thermal conductivity material mentioned above ensures that the heat generated by the COS component 300 is quickly conducted away through the heat sink 100, further guaranteeing long-term reliability under high power output conditions.

[0069] Compared with existing technologies, the semiconductor laser based on multi-step dense packaging provided by this invention effectively utilizes the unused space above the step arrays by setting a first step array 210 and a second step array 220 oppositely arranged on the heat sink 100 and adopting a complementary forward and inverted mounting method, significantly reducing the horizontal width occupied by the optical path unit. Under the condition of the same number of light-emitting units, the overall size of the heat sink 100 is significantly reduced, and the module weight is lowered. This makes the semiconductor laser based on multi-step dense packaging suitable for handheld devices, UAV-borne laser systems, and space-constrained industrial processing scenarios, expanding its lightweight and high-power application range.

[0070] Secondly, by designing a stepped surface height that decreases synchronously along the first direction DX and the second direction DY, all stepped surfaces are spatially distributed with equal gradients, ensuring that the optical path transmission distance between each COS component 300 installed on the corresponding stepped surface and the corresponding SAC component 420 is completely consistent. Based on this equal optical path distance, all SAC components 420 can use the same focal length specification, eliminating the need to configure slow-axis collimating lenses with different focal lengths for different columns or layers. This significantly reduces the types of materials, lowers inventory and procurement costs, simplifies the assembly process, and avoids the complex focal length management problems caused by mixing multiple SAC specifications, which is beneficial for mass production and quality control.

[0071] Furthermore, since all optical paths have equal transmission distances and the SAC component 420 uses a uniform focal length, each beam has a consistent spot size and divergence angle after slow-axis collimation, eliminating the problems of inconsistent spot size and beam quality caused by focal length differences in traditional structures. After fast-axis collimation (divergence angle ≤ 2mrad) and slow-axis collimation (divergence angle ≤ 1.5mrad), each beam has highly consistent quality parameters before spatial beam combining. This effectively reduces beam combining loss, improves beam combining efficiency and output beam quality when the beam is subsequently turned and combined by the reflector component 430, which is beneficial for obtaining laser output with higher power density and better beam uniformity.

[0072] In summary, this invention, through the aforementioned multi-level gradient step combination structure and integrated heat sink 100 design, effectively solves the prominent problems in the prior art, such as the numerous specifications of SAC component 420, poor beam consistency, insufficient integration, and limited heat dissipation, while ensuring the consistency of optical performance and the quality of output beam. It has significant technological advancements and broad industrial application prospects.

[0073] In the description herein, it should be understood that the terms "upper," "lower," "left," and "right," etc., of orientation or positional relationship, are used only for ease of description and simplification of operation, 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. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no special meaning.

[0074] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0075] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0076] The technical principles of this application have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this application without inventive effort, and these embodiments will all fall within the scope of protection of this application.

Claims

1. A semiconductor laser based on multi-stage step-dense packaging, characterized in that, include: A heat sink (100) has a bottom surface (110) and a top surface (120) arranged in parallel and opposite directions. A first stepped array (210) is connected to the bottom surface (110), and a second stepped array (220) is connected to the top surface (120). The first stepped array (210) and the second stepped array (220) are installed in a complementary manner with the first and second steps being upright and inverted. Both the first stepped array (210) and the second stepped array (220) include multiple stepped surfaces arranged in an array along the first direction (DX) and the second direction (DY), and the distance between the corresponding stepped surface on each stepped array and the bottom surface (110) decreases from large to small along the first direction (DX) and the second direction (DY). In one of the stepped arrays, a laser module is installed on the stepped surface, and an optical component is installed on the stepped surface of the other stepped array. The number of laser modules and optical components are equal and they correspond one-to-one.

2. The semiconductor laser based on multi-stage step-dense packaging according to claim 1, characterized in that, Along the first direction (DX) and the second direction (DY), the step surface on the first stair array (210) can be defined as Txy, and the step surface on the second stair array (220) can be defined as Sxy, where x and y are positive integers greater than 0; Wherein, the step surfaces with the same subscript in the first step array (210) and the second step array (220) have a mapping relationship, the mapping relationship including: Two stepped surfaces with a mapping relationship have a preset first offset in the first direction (DX); and a preset second offset in a third direction (DZ) perpendicular to the bottom surface (110); and the stepped surfaces with the same subscripts of the first stepped array (210) and the second stepped array (220) are respectively used to connect the laser module and the optical component with a corresponding relationship.

3. The semiconductor laser based on multi-stage step-dense packaging according to claim 1, characterized in that, The first direction (DX) and the second direction (DY) are perpendicular to each other.

4. The semiconductor laser based on multi-stage step-dense packaging according to claim 1, characterized in that, Along the first direction (DX), the height difference between adjacent step surfaces is a first fixed value (Dh1); and along the second direction (DY), the height difference between adjacent step surfaces is a second fixed value (Dh2).

5. The semiconductor laser based on multi-stage step-dense packaging according to claim 1, characterized in that, The laser module includes a COS component (300), and the heating surface of the COS component (300) is in contact with the corresponding stepped surface it is mounted on.

6. The semiconductor laser based on multi-stage step-dense packaging according to claim 1, characterized in that, The optical element includes: The FAC component (410) is correspondingly disposed at the laser emitting end of each of the COS components (300) for fast-axis collimation of the laser; and SAC component (420) is mounted on the stepped surface of another stepped array corresponding to COS component (300) for slow-axis collimation of the laser beam emitted by the corresponding COS component (300).

7. The semiconductor laser based on multi-stage stepped dense packaging according to claim 1, characterized in that, The optical element further includes a mirror assembly (430) and the SAC assembly (420) mounted on the same step surface, used to adjust the beam direction of the laser beam collimated by the SAC assembly (420).

8. The semiconductor laser based on multi-stage stepped dense packaging according to claim 7, characterized in that, The heat sink (100) has a light-emitting window (500) located on the optical path of the laser beam after it has been adjusted by the reflector assembly (430).

9. The semiconductor laser based on multi-stage step-dense packaging according to claim 1, characterized in that, The heat sink (100) is provided with a heat dissipation structure (600), which is located on one side of the laser module and is used to exchange heat with the laser module.

10. The semiconductor laser based on multi-stage step-dense packaging according to claim 1, characterized in that, An electrode (700) is also fixed on the heat sink (100). The inner side of the electrode (700) is electrically connected to each of the laser modules, and the outer side of the electrode (700) is used to connect to an external power supply.

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