Anti-reflection semiconductor laser device

Abstract

The invention discloses an anti-reflection semiconductor laser device which comprises a base, a tube tongue, a heat sink, a semiconductor laser chip, a tube pin and a tube cap. The tube tongue is arranged on the base, the heat sink is fixed on the tube tongue, the semiconductor laser chip is fixed on the heat sink, the tube pin is fixed at the bottom of the base, the tube cap covers the base, and the tube cap comprises a tube shell and a light window; the tube tongue, the heat sink, the semiconductor laser chip and the tube cap all adopt a partial or total anti-reflection structural design. Through structural optimization and functional modification of core components such as the tube tongue, the heat sink, the semiconductor laser chip and the tube cap, all-directional and efficient suppression of primary reflection light of an optical element is achieved, the working stability of a device is remarkably improved, the service life of the device is remarkably prolonged, and the actual application requirements of the fields of sensing, display, communication and the like are met.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optoelectronic device technology, and more particularly to an anti-reflective semiconductor laser device. Background Technology

[0002] Semiconductor laser devices, with their significant advantages such as small size, high electro-optical conversion efficiency, and long operating life, have been widely used in many core fields such as indication, sensing, display, and communication. Among them, the TO package structure has become one of the most mainstream packaging forms for semiconductor lasers due to its compact structure, low manufacturing cost, and excellent compatibility with external circuits. A typical TO packaged semiconductor laser device mainly consists of core components such as pin 5, base 1, tongue 2, heat sink 3, semiconductor laser chip 4, and cap 6. The semiconductor laser chip 4 is fixed to the surface of the tongue 2 by the heat sink 3, which achieves both mechanical fixation and efficient heat conduction. The cap 6 covers the base 1 and mainly consists of two parts: the shell 6-1 and the optical window 6-2, which protects all internal components. The device structure is as follows. Figure 1 , Figure 2 and Figure 3 As shown.

[0003] Because semiconductor lasers emit light divergently, they typically require collimation and shaping using an optical lens 7 in practical applications. Due to reflection on the surface of the optical lens, the laser beam emitted from the device will inevitably be reflected back towards the laser device, forming a primary reflection. This primary reflection is then reflected again by the upper surface of the nozzle 2, the side of the heat sink 3, the light-emitting surface of the semiconductor laser chip 4, and the upper surface of the cap 6 within the laser device, forming a secondary reflection. Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, 8-1 represents the initial laser emission ray, 8-2 represents the primary reflected ray formed by the optical lens, and 8-3 represents the secondary reflected ray from the side of the nozzle 2, heat sink 3, the light-emitting surface of the semiconductor laser chip 4, or the upper surface of the nozzle cap 6. These secondary reflected rays can form secondary light spots that deviate from the main axis of the laser beam, thus affecting the beam quality. Simultaneously, stray light interference can reduce the accuracy of high-speed communication and sensing measurements, directly and adversely affecting the application of laser devices in fields such as indication, sensing, display, and communication.

[0004] In existing technologies, anti-reflection treatment solutions for TO-packaged semiconductor laser devices mostly focus on using anti-reflection coatings on optical lenses or adding optical isolators to the optical path. These solutions are structurally complex, leading to increased device costs and affecting the overall compactness of the assembly, making it difficult to meet the miniaturization requirements of practical applications. Therefore, developing a semiconductor laser device with a simple structure, controllable cost, excellent anti-reflection performance, and without affecting the original operating performance has become a critical technical problem urgently needing to be solved in the current semiconductor laser field. Summary of the Invention

[0005] To address the shortcomings of existing TO-packaged semiconductor laser devices, such as insufficient suppression of primary reflections from optical elements and poor device stability, this invention provides an anti-reflection semiconductor laser device. By optimizing the structure and modifying the functions of core components such as the nozzle, heat sink, semiconductor laser chip, and nozzle cap, comprehensive and efficient suppression of primary reflections from optical elements is achieved, significantly improving the device's operational stability and lifespan, thus meeting the practical application needs in sensing, display, and communication fields.

[0006] The present invention provides an anti-reflection semiconductor laser device, comprising a base, a tongue, a heat sink, a semiconductor laser chip, pins, and a cap; the tongue is disposed on the base, the heat sink is fixed on the tongue, the semiconductor laser chip is fixed on the heat sink, the pins are fixed to the bottom of the base, and the cap covers the base, the cap comprising a shell and an optical window; the tongue, heat sink, semiconductor laser chip, and cap all adopt a partial or full anti-reflection structure design.

[0007] Preferably, the anti-reflective structure of the tongue is implemented in at least one of the following ways: The top of the tongue is machined with a reflective structure, which includes any shape among inclined surface, conical surface, arc surface, serrated, frosted or stepped. The upper surface of the tongue is covered with a reflective structure, which includes any shape among inclined surface, conical surface, arc surface, sawtooth, frosted or stepped. The upper surface of the tube tongue is covered with a light-absorbing layer.

[0008] Preferably, the anti-reflective structure design of the heat sink is achieved through at least one of the following methods: The heat sink has a reflective structure processed on its side corresponding to the laser emission direction. The reflective structure includes any shape among inclined surface, conical surface, arc surface, sawtooth shape, frosted shape or stepped shape. The heat sink is covered with a reflective structure on the side corresponding to the laser emission direction. The reflective structure includes any shape among inclined surface, conical surface, arc surface, sawtooth shape, frosted shape or stepped shape. The heat sink has a light-absorbing layer covering the side facing the direction of laser light emission.

[0009] Preferably, the anti-reflective structure design of the tube shell is achieved through at least one of the following methods: The top of the tube shell is machined with a reflective structure, which includes any shape among inclined surface, conical surface, arc surface, sawtooth shape, frosted shape or stepped shape; The upper surface of the tube shell is covered with a reflective structure, which includes any shape among inclined surface, conical surface, arc surface, sawtooth, frosted or stepped. The upper surface of the tube shell is covered with a light-absorbing layer.

[0010] Preferably, the reflective structure at the top of the tube tongue, the reflective structure covering the upper surface of the tube tongue, the reflective structure on the side of the heat sink, the reflective structure covering the side of the heat sink, the reflective structure at the top of the tube shell, and the reflective structure covering the upper surface of the tube shell all have the ability to reflect or diffusely reflect the emission wavelength of the semiconductor laser chip at a large angle. This can reflect the primary reflected light from the optical element to other directions, preventing the secondary reflected light from returning to the optical path.

[0011] Preferably, the light absorption layer covering the upper surface of the tube tongue, the light absorption layer covering the side of the heat sink, and the light absorption layer covering the upper surface of the tube shell all have strong light absorption capabilities for the emission wavelength of the laser chip, which can absorb the first reflected light reflected back from the optical element and prevent the second reflected light from returning to the optical path.

[0012] Preferably, the reflective structure covering the upper surface of the tongue, the reflective structure covering the side of the heat sink, and the reflective structure covering the upper surface of the shell are formed by directly covering Ag glue, UV-curable glue, epoxy resin, and solder paste, which are applied to the surface of the tongue using a dispensing process and then treated by heat curing and light exposure to form a solid reflective structure; or Ag glue, UV-curable glue, epoxy resin, and solder paste are used as adhesive layers and bonded using dispensing and die bonding processes.

[0013] Preferably, the light-absorbing layer covering the upper surface of the tube tongue, the side of the heat sink, and the upper surface of the tube shell uses Ag glue, UV-curable adhesive, metal absorption film, and semiconductor absorption layer light-absorbing materials. The Ag glue and UV-curable adhesive gel-like absorption layer can be applied to the surface of the tube tongue using a dispensing process, and then formed into a solid absorption layer after heat curing and light irradiation. The metal absorption film and semiconductor absorption layer solid absorption layer are prepared using evaporation and sputtering methods. The light-absorbing layer can also be a light-absorbing sheet, using Ag glue, UV-curable adhesive, epoxy resin, and solder paste as adhesive layers, and bonded using dispensing and die bonding processes. The absorption wavelength of the light-absorbing layer includes the emission wavelength of the semiconductor laser chip, and the higher the absorption rate, the better.

[0014] Preferably, the anti-reflection structure design of the semiconductor laser chip is achieved through at least one of the following methods: A light-reflecting structure is covered at the bottom of the light-emitting surface of the semiconductor laser chip; The bottom of the light-emitting surface of a semiconductor laser chip is covered with a light-absorbing structure.

[0015] Preferably, the light-reflecting structure covering the bottom of the light-emitting surface of the semiconductor laser chip has optical diffuse reflection capability for its emission wavelength, reflecting the primary reflected light reflected from the optical element back to the side of the semiconductor laser chip to other directions, preventing the secondary reflected light from returning to the optical path; the light-absorbing structure at the bottom of the light-emitting surface of the semiconductor laser chip absorbs wavelengths that include its emission wavelength, and the higher the absorption rate, the better, effectively absorbing the primary reflected light reflected from the optical element back to the side of the semiconductor laser chip, thereby reducing the intensity of the secondary reflected light.

[0016] Preferably, the light-reflecting structure covering the bottom of the light-emitting surface of the semiconductor laser chip is a metal reflective layer, a semiconductor reflective layer, and a surface microstructure; the light-absorbing structure at the bottom of the light-emitting surface of the semiconductor laser chip is a metal absorber layer and a semiconductor absorber layer; the aforementioned metal reflective layer, semiconductor reflective layer, surface microstructure, metal absorber layer, and semiconductor absorber layer are prepared by vapor deposition and sputtering methods.

[0017] Preferably, the cap is a windowless cap or a transparent cap, and the light window of the transparent cap is coated with an antireflection film for the emission wavelength of the semiconductor laser chip. The antireflection film adopts an SiO2, TiO2, or Ta2O5 oxide optical film system.

[0018] Preferably, the heat sink is made of a high thermal conductivity material, including AlN, SiC, and diamond.

[0019] Preferably, the tongue and the base are integrally formed or fixedly connected by welding or bonding; the heat sink and the tongue, and the semiconductor laser chip and the heat sink are all fixedly bonded by AuSn alloy or thermally conductive adhesive.

[0020] Compared with the prior art, the anti-reflection semiconductor laser device provided by the embodiments of the present invention has the following advantages: Highly efficient suppression of stray light: By setting reflective or light-absorbing structures on several key components (tube tongue, heat sink, semiconductor laser chip, tube cap) that are prone to reflection inside the laser device, the primary reflected light from external optical elements can be reflected to other directions or absorbed, thus preventing the primary reflected light from returning to the optical path from the source and effectively suppressing stray light from optical components.

[0021] Improving beam quality and system accuracy: By effectively suppressing stray light and avoiding the formation of secondary light spots or background noise around the main beam, the quality of the output beam is significantly improved. This is of paramount importance for applications that rely on high-quality beams and high signal-to-noise ratios, such as high-end indication, high-precision sensing, high-speed optical communication, and laser displays, as it directly improves the system's measurement accuracy and signal transmission reliability.

[0022] Compact structure and low cost: This method eliminates the need for complex and expensive optical isolators in the optical path, and avoids requiring special anti-reflective coatings on the external optical lenses. Anti-reflective functionality is achieved simply by surface treatment or coating of existing internal components. This approach does not alter the original structure and size of the TO package, maintaining its miniaturization advantage. Furthermore, the process is simple, easy to mass-produce, and cost-effective. Attached Figure Description

[0023] Figure 1 A schematic diagram of the planar structure of a semiconductor laser device (excluding the cap portion); Figure 2 A schematic diagram of the planar structure of a semiconductor laser device (including the cap portion). Figure 3 A schematic diagram of the side structure of a semiconductor laser device; Figure 4 A schematic diagram of the reflection of stray light from the laser component on the upper surface of the nozzle; Figure 5 A schematic diagram of stray light from the laser component reflected on the side of the heat sink; Figure 6 A schematic diagram of stray light from a laser component reflecting off the light-emitting surface of a semiconductor laser chip; Figure 7 A schematic diagram of the reflection of stray light from the laser assembly on the upper surface of the cap; Figure 8 A schematic diagram showing the processing of various reflective structures on the top of the tongue; Figure 9 A schematic diagram showing the various anti-reflective principles applied to the top of the tongue; Figure 10 Schematic diagram of multiple reflective structures covering the tongue of the tube; Figure 11 Schematic diagram of the light-absorbing layer covering the surface of the tube tongue; Figure 12 Schematic diagram of heat sink anti-reflection treatment; Figure 13 Schematic diagram of the anti-reflection structure on the side of a semiconductor laser chip; Figure 14 Schematic diagram of various reflective structures fabricated in the tube shell; Figure 15Schematic diagram of a tube shell covered with multiple reflective structures; Figure 16 Schematic diagram of the tube shell covering absorption layer structure; Figure 17 This is a schematic diagram of the structure of an embodiment of the present invention.

[0024] In the diagram: 1. Base; 2. Tongue; 2-1. Tongue diffuse reflection structure; 2-2. First adhesive layer; 2-3. Tongue reflection structure; 2-4. Tongue light absorption layer; 2-5. Second adhesive layer; 3. Heat sink; 3-1. Heat sink diffuse reflection structure; 3-2. Third adhesive layer; 3-3. Heat sink reflection structure; 3-4. Heat sink light absorption layer; 4. Semiconductor laser chip; 4-1. Location of light reflection or light absorption structure; 4-2. Ridge waveguide; 4-3. Laser... Location of light emission point; 5. Pin; 6. Cap; 6-1. Shell; 6-1-1. Rough shell surface; 6-1-2. Large-angle shell reflection structure; 6-2. Light window; 6-3. Shell diffuse reflection structure; 6-4. Fourth adhesive layer; 6-5. Shell reflection structure; 6-6. Shell light absorption layer; 6-7. Fifth adhesive layer; 7. Optical lens; 8-1. Initial laser emission ray; 8-2. First reflection ray; 8-3. Second reflection ray. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] To address the aforementioned issues, the following specific embodiments will provide a detailed description and explanation of an anti-reflection semiconductor laser device provided in this application.

[0027] Reference Figure 1-17 The present invention provides an anti-reflection semiconductor laser device, comprising a base 1, a tongue 2, a heat sink 3, a semiconductor laser chip 4, pins 5, and a cap 6; the tongue 2 is disposed on the base 1, the heat sink 3 is fixed on the tongue 2, the semiconductor laser chip 4 is fixed on the heat sink 3, the pins 5 are fixed to the bottom of the base 1, and the cap 6 covers the base 1, the cap 6 comprising a shell 6-1 and an optical window 6-2; the tongue 2, the heat sink 3, the semiconductor laser chip 4, and the cap 6 all adopt a partial or full anti-reflection structure design.

[0028] The anti-reflective structure of the tongue is achieved through at least one of the following methods: The top of the tongue 2 is machined with a reflective structure, which includes any shape among inclined surfaces, conical surfaces, arc surfaces, serrated surfaces, frosted surfaces, or stepped surfaces, such as... Figure 8 (a) and Figure 8 As shown in (b), the reflective structure on the nozzle is processed into inclined surfaces in different directions, such as... Figure 8 (c) and Figure 8 As shown in (d), the reflective structure on the tongue is processed into a conical surface and a sawtooth shape. The top reflective structure of the tongue 2 has the ability to reflect or diffusely reflect the wavelength emitted by the laser chip at a large angle. It can reflect the primary reflected light 8-2 that was reflected back to the upper surface of the tongue by the optical element to other directions, preventing the secondary reflected light 8-3 from returning to the optical path. The principle is as follows: Figure 9 (a) and Figure 9 As shown in (b), Figure 9 (a) The principle is to use large-angle reflection to reflect light in other directions. Figure 9 (b) The principle is to use diffuse reflection to disperse light to all parts of space.

[0029] The upper surface of the tongue 2 is covered with a reflective structure, which includes any shape among inclined surfaces, conical surfaces, arc surfaces, sawtooth shapes, frosted surfaces, or stepped shapes. The reflective structure can be formed by directly covering the surface with substances such as Ag glue, UV-curable adhesive, epoxy resin, and solder paste. These substances can be applied to the surface of the tongue 2 using a dispensing process and then treated by heat curing, light exposure, or other methods to form a solid reflective structure, such as... Figure 10 As shown in (a), 2-1 is a coated diffuse reflection structure for the tongue, which can be formed by coating and curing a gel-like substance. Ag glue, UV-curable adhesive, and other substances, after curing, possess both diffuse reflection and light absorption properties, making them the preferred reflective layer. The reflective structure can also be formed through other processing methods, and then Ag glue, UV-curable adhesive, epoxy resin, solder paste, and other substances are used as adhesive layers, bonded to the upper surface of the tongue 2 using dispensing and die bonding processes, such as... Figure 10 As shown in (b), the first adhesive layer 2-2 is the adhesive material, and 2-3 is the tongue-and-groove reflective structure. The anti-reflection principle of the reflective structure covering the upper surface of the tongue-and-groove 2 is the same as... Figure 9 The principle is the same.

[0030] The upper surface of the nozzle 2 is covered with a light-absorbing layer. This light-absorbing layer can be made directly from light-absorbing materials such as Ag glue, UV-curable adhesive, metal absorbing film, or semiconductor absorbing layer. Ag glue and UV-curable adhesives can be applied to the upper surface of the nozzle using a dispensing process, and then cured by heat, light, or other methods to form a solid absorption layer. Metal absorbing films and semiconductor absorbing layers can be prepared using methods such as evaporation or sputtering. Figure 11As shown in (a), the light-absorbing layers 2-4 of the tube tongue are formed by direct overlay. Ag glue, UV-curable adhesive, and other substances possess both light-absorbing and diffuse reflection properties, making them the preferred choice for the absorption layer. The light-absorbing layer can also be formed through other processing methods, such as directly using a light-absorbing sheet, and then using Ag glue, UV-curable adhesive, epoxy resin, solder paste, etc., as adhesive layers, bonded to the upper surface of the tube tongue 2 using dispensing and die bonding processes, as shown in (a). Figure 11 As shown in (b), the light-absorbing layer 2-4 of the tube tongue is bonded to the tube tongue 2 via the second adhesive layer 2-5. The absorption wavelength of the light-absorbing layer includes the emission wavelength of the semiconductor laser chip, and the higher the absorption rate, the better. By utilizing the absorption of the primary reflected light 8-2 by the light-absorbing layer, the intensity of the secondary reflected light 8-3 can be effectively reduced.

[0031] The anti-reflection structure design of the heat sink 3 is achieved through at least one of the following methods: The heat sink 3 has a reflective structure processed on its side corresponding to the laser emission direction. This reflective structure can be any shape, including an inclined surface, a conical surface, an arc surface, a sawtooth shape, a frosted surface, or a stepped shape. For example... Figure 12 As shown in (a), 3-1 is a coated heat sink diffuse reflection structure, which can be formed by coating and curing a gel-like substance. Ag glue, UV-curable glue, and other substances, after curing, possess both diffuse reflection and light absorption properties, making them the preferred choice for reflective layers. The side reflection structure of the heat sink 3 has the ability to reflect or diffusely reflect the wavelength emitted by the laser chip at a large angle. It can reflect the primary reflected light 8-2, which is reflected back to the side of the heat sink 3 from the optical element, to other directions, preventing the secondary reflected light 8-3 from returning to the optical path. The anti-reflection principle of the side reflection structure of the heat sink 3 is similar to... Figure 9 The principle is the same.

[0032] The heat sink 3 has a reflective structure covering its side facing the laser emission direction. This reflective structure can be any shape, including an inclined surface, a conical surface, an arc surface, a serrated surface, a frosted surface, or a stepped surface. The reflective structure can be formed by directly covering it with adhesive substances such as Ag glue, UV-curable adhesive, epoxy resin, or solder paste. Figure 12 As shown in (a), these materials can be coated onto the sides of the heat sink 3 using a dispensing process, and then treated by thermosetting, light exposure, or other methods to form a solid reflective structure. The reflective structure can also be formed by other methods, and then bonded to the sides of the heat sink 3 using substances such as Ag glue, UV-curable adhesive, epoxy resin, and solder paste as adhesive layers, employing dispensing and die bonding processes, as shown in (a). Figure 12 As shown in (b), the third adhesive layer 3-2 is an adhesive material, and 3-3 is a heat sink reflective structure. The anti-reflection principle of the heat sink 3 side-covered reflective structure is similar to... Figure 9 The principle is the same.

[0033] A light-absorbing layer is applied to the side of heat sink 3 corresponding to the laser emission direction. This light-absorbing layer can be made directly from light-absorbing materials such as Ag glue, UV-curable adhesive, metal absorption film, or semiconductor absorption layer. Ag glue, UV-curable adhesive, and other gel-like absorption layers can be applied to the side of heat sink 3 using a dispensing process, and then cured by heat, light, or other methods to form a solid absorption layer. Solid absorption layers such as metal absorption films and semiconductor absorption layers can be prepared using methods such as evaporation or sputtering. Figure 12 As shown in (c), the heat sink light absorption layer 3-4 is formed by direct overlay. Ag glue, UV-curable adhesive, and other substances possess both light absorption and diffuse reflection properties, making them the preferred choice for the absorption layer. The light absorption layer can also be formed through other processing methods, such as directly using a light-absorbing sheet and then using Ag glue, UV-curable adhesive, epoxy resin, solder paste, or other substances as adhesive layers, bonded to the side of the heat sink 3 using dispensing and die bonding processes. The absorption wavelength of the light absorption layer includes the emission wavelength of the semiconductor laser chip; the higher the absorption rate, the better. Utilizing the absorption of the primary reflected light 8-2 by the light absorption layer can effectively reduce the intensity of the secondary reflected light 8-3.

[0034] The anti-reflective structure design of the tube shell 6-1 is achieved through at least one of the following methods: The top of the housing 6-1 is machined with a reflective structure, which includes any shape among inclined surfaces, conical surfaces, arc surfaces, sawtooth shapes, frosted surfaces, or stepped shapes. The top reflective structure of the housing 6-1 has the capability of large-angle reflection or diffuse reflection of the laser chip's emitted wavelength. It can reflect the primary reflected light rays that have been reflected back to the upper surface of the housing 6-1 by the optical element to other directions, preventing stray secondary reflected light rays from returning to the optical path. Figure 14 As shown, Figure 14 (a) is the rough shell surface 6-1-1, which has diffuse reflection capability. Figure 14 (b) is the large-angle tube shell reflective structure 6-1-2. The anti-reflection principle of the top reflective structure of tube shell 6-1 is the same as... Figure 9 The principle is the same.

[0035] The upper surface of the tube shell 6-1 is covered with a reflective structure, which includes any shape among inclined surfaces, conical surfaces, arc surfaces, serrated surfaces, frosted surfaces, or stepped surfaces. The reflective structure can be formed by directly covering it with adhesive substances such as Ag glue, UV-curable adhesive, epoxy resin, and solder paste. These substances can be applied to the surface of the tube tongue using a dispensing process and then treated by heat curing, light exposure, or other methods to form a solid reflective structure, such as... Figure 15As shown in (a), 6-3 is a coated diffuse reflection structure for the tube shell, which can be formed by coating and curing a gel-like substance. Ag glue, UV-curable adhesive, and other substances, after curing, possess both diffuse reflection and light absorption properties, making them the preferred reflective layer. The reflective structure can also be formed through other processing methods, and then Ag glue, UV-curable adhesive, epoxy resin, solder paste, etc., are used as adhesive layers, bonded to the upper surface of the tube shell 6-1 using dispensing and die bonding processes, as shown in (a). Figure 15 As shown in (b), the fourth adhesive layer 6-4 is the adhesive material, and 6-5 is the reflective structure of the tube shell. The anti-reflection principle of the special-shaped reflective structure covering the tube shell 6-1 is... Figure 9 The principle is the same.

[0036] The upper surface of the tube shell 6-1 is covered with a light-absorbing layer. This light-absorbing layer can be made directly from light-absorbing materials such as Ag glue, UV-curable adhesive, metal absorbing film, or semiconductor absorbing layer. Ag glue, UV-curable adhesive, and other gel-like absorbing layers can be applied to the upper surface of the tube shell 6-1 using a dispensing process, and then cured by heat, light, or other methods to form a solid absorbing layer. Solid absorbing layers such as metal absorbing film and semiconductor absorbing layer can be prepared using methods such as evaporation or sputtering. Figure 16 As shown in (a), the light-absorbing layer 6-6 of the tube shell is formed by direct overlay. Ag glue, UV-curable adhesive, and other substances possess both light-absorbing and diffuse reflection properties, making them the preferred choice for the absorption layer. The light-absorbing layer can also be formed through other processing methods, such as directly using a light-absorbing sheet, and then using Ag glue, UV-curable adhesive, epoxy resin, solder paste, etc., as adhesive layers, bonded to the upper surface of the tube shell 6-1 using dispensing and die bonding processes, as shown in (a). Figure 16 As shown in (b), the light-absorbing layer 6-6 of the tube shell is bonded to the tube shell 6-1 through the fifth adhesive layer 6-7. The absorption wavelength of the light-absorbing layer includes the emission wavelength of the semiconductor laser chip, and the higher the absorption rate, the better. By utilizing the absorption of the primary reflected light 8-2 by the light-absorbing layer, the intensity of the secondary reflected light 8-3 can be effectively reduced.

[0037] The anti-reflection structure design of the semiconductor laser chip 4 is achieved through at least one of the following methods: The bottom of the light-emitting surface of the semiconductor laser chip 4 is covered with a light-reflecting structure; this achieves diffuse reflection of the first reflected light beam 8-2. For example... Figure 13 The laser chip shown has an emitting surface, with 4-2 representing the ridge waveguide, 4-3 the laser emission point, and 4-1 the location of the light-reflecting or light-absorbing structure. The smaller the perpendicular distance between the interface and the emission point 4-3, the better the effect. The light-reflecting structure can be a semiconductor reflective layer, a metal reflective layer, or a surface microstructure. The light-reflecting structure must have optical diffuse reflection capability for the emission wavelength of the semiconductor laser chip. These metal reflective layers, semiconductor reflective layers, and surface microstructures can be fabricated using methods such as evaporation and sputtering.

[0038] The bottom of the light-emitting surface of the semiconductor laser chip 4 is covered with a light-absorbing structure to absorb the first reflected light 8-2. For example... Figure 13 The light-emitting surface of the laser chip shown is 4-1, which represents the location of the light-reflecting or light-absorbing structure. The smaller the vertical distance between this interface and the light-emitting point 4-3, the better the effect. The light-absorbing structure can be a semiconductor absorption layer, a metal absorption layer, etc. The absorption wavelength of the light-absorbing structure must include the emission wavelength of the semiconductor laser chip, and the higher the absorption rate, the better. These metal absorption layers, semiconductor absorption layers, etc., can be prepared using methods such as evaporation and sputtering.

[0039] The light-reflecting structure covering the bottom of the light-emitting surface of the semiconductor laser chip 4 has optical diffuse reflection capability for its emission wavelength, reflecting the primary reflected light 8-2 reflected back to the side of the semiconductor laser chip 4 by the optical element to other directions, thus preventing the secondary reflected light 8-3 from returning to the optical path; the light-absorbing structure at the bottom of the light-emitting surface of the semiconductor laser chip 4 absorbs wavelengths that include its emission wavelength, and the higher the absorption rate, the better, effectively absorbing the primary reflected light 8-2 reflected back to the side of the semiconductor laser chip 4 by the optical element, thereby reducing the intensity of the secondary reflected light 8-3.

[0040] The light-reflecting structure covering the bottom of the light-emitting surface of the semiconductor laser chip 4 is a metal reflective layer, a semiconductor reflective layer, and a surface microstructure; the light-absorbing structure at the bottom of the light-emitting surface of the semiconductor laser chip 4 is a metal absorption layer and a semiconductor absorption layer; the aforementioned metal reflective layer, semiconductor reflective layer, surface microstructure, metal absorption layer, and semiconductor absorption layer are prepared by vapor deposition and sputtering methods.

[0041] The cap 6 is either a windowless cap or a transparent cap. The transparent cap has an anti-reflection coating at the optical window 6-2, specifically designed for the emission wavelength of the semiconductor laser chip. This anti-reflection coating is made of SiO2, TiO2, or Ta2O5 oxide optical film system. The anti-reflection coating significantly reduces the reflection of the primary reflected light 8-2 by the optical window 6-2. The heat sink 3 is made of a high thermal conductivity material, including AlN, SiC, and diamond. The tongue 2 and the base 1 are integrally formed or fixedly connected by welding or bonding. The heat sink 3 and the tongue 2, as well as the semiconductor laser chip 4 and the heat sink 3, are all fixedly bonded using AuSn alloy or thermally conductive adhesive.

[0042] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An anti-reflective semiconductor laser device, comprising a base (1), a tongue (2), a heat sink (3), a semiconductor laser chip (4), pins (5), and a cap (6); wherein the tongue (2) is disposed on the base (1), the heat sink (3) is fixed on the tongue (2), the semiconductor laser chip (4) is fixed on the heat sink (3), the pins (5) are fixed to the bottom of the base (1), and the cap (6) covers the base (1), the cap (6) comprising a shell (6-1) and an optical window (6-2); characterized in that: The tongue (2), heat sink (3), semiconductor laser chip (4), and cap (6) all adopt a partial or full anti-reflection structure design.

2. The anti-reflection semiconductor laser device according to claim 1, characterized in that, The anti-reflective structure of the tongue is achieved through at least one of the following methods: The top of the tongue (2) is processed with a reflective structure, which includes any shape among inclined surface, conical surface, arc surface, sawtooth shape, frosted shape or stepped shape; The upper surface of the tongue (2) is covered with a reflective structure, which includes any shape among inclined surface, conical surface, arc surface, sawtooth, frosted or stepped; The upper surface of the tongue (2) is covered with a light-absorbing layer.

3. The anti-reflection semiconductor laser device according to claim 1, characterized in that: The anti-reflective structure design of the heat sink (3) is achieved through at least one of the following methods: The heat sink (3) has a reflective structure on the side corresponding to the laser emission direction. The reflective structure includes any shape among inclined surface, conical surface, arc surface, sawtooth shape, frosted shape or stepped shape. The heat sink (3) has a reflective structure on the side corresponding to the laser emission direction. The reflective structure includes any shape among inclined surface, conical surface, arc surface, sawtooth shape, frosted shape or stepped shape. The side of the heat sink (3) corresponding to the laser emission direction is covered with a light absorption layer.

4. The anti-reflection semiconductor laser device according to claim 1, characterized in that: The anti-reflective structure design of the tube shell (6-1) is achieved through at least one of the following methods: The top of the tube shell (6-1) is machined with a reflective structure, which includes any shape among inclined surface, conical surface, arc surface, sawtooth, frosted or stepped. The upper surface of the tube shell (6-1) is covered with a reflective structure, which includes any shape among inclined surface, conical surface, arc surface, sawtooth, frosted or stepped. The upper surface of the tube shell (6-1) is covered with a light-absorbing layer.

5. An anti-reflection semiconductor laser device according to any one of claims 2, 3, and 4, characterized in that: The reflective structure at the top of the tongue (2), the reflective structure covering the upper surface of the tongue (2), the reflective structure on the side of the heat sink (3), the reflective structure covering the side of the heat sink (3), the reflective structure at the top of the shell (6-1), and the reflective structure covering the upper surface of the shell (6-1) all have the ability to reflect or diffusely reflect the emission wavelength of the semiconductor laser chip at a large angle. They can reflect the first reflected light (8-2) reflected back from the optical element to other directions, and prevent the second reflected light (8-3) from returning to the optical path again.

6. An anti-reflection semiconductor laser device according to any one of claims 2, 3, and 4, characterized in that: The light absorption layer covering the upper surface of the tube tongue (2), the light absorption layer covering the side of the heat sink (3), and the light absorption layer covering the upper surface of the tube shell (6-1) all have strong light absorption capabilities for the emission wavelength of the laser chip, which can absorb the first reflected light (8-2) reflected back by the optical element and prevent the second reflected light (8-3) from returning to the optical path again.

7. An anti-reflection semiconductor laser device according to any one of claims 2, 3, and 4, characterized in that: The reflective structure covering the upper surface of the tongue (2), the reflective structure covering the side of the heat sink (3), and the reflective structure covering the upper surface of the shell (6-1) are formed by directly covering Ag glue, UV curing glue, epoxy resin, and solder paste. The glue is applied to the surface of the tongue using a dispensing process and then treated by heat curing and light irradiation to form a solid reflective structure. Alternatively, Ag glue, UV curing glue, epoxy resin, and solder paste can be used as adhesive layers and bonded using dispensing and die bonding processes.

8. An anti-reflection semiconductor laser device according to any one of claims 2, 3, and 4, characterized in that: The upper surface of the tube tongue (2) is covered with a light-absorbing layer, the side of the heat sink (3) is covered with a light-absorbing layer, and the upper surface of the tube shell (6-1) is covered with a light-absorbing layer using Ag glue, UV-curable glue, metal absorption film, and semiconductor absorption layer light-absorbing materials. The Ag glue and UV-curable glue gel-like absorption layer can be coated on the surface of the tube tongue using a dispensing process, and after heat curing and light irradiation, a solid absorption layer is formed. The metal absorption film and semiconductor absorption layer solid absorption layer are prepared by evaporation and sputtering methods. The light-absorbing layer can also use a light-absorbing sheet, using Ag glue, UV-curable glue, epoxy resin, and solder paste as adhesive layers, and is bonded using dispensing and die bonding processes. The absorption wavelength of the light-absorbing layer includes the emission wavelength of the semiconductor laser chip, and the higher the absorption rate, the better.

9. The anti-reflection semiconductor laser device according to claim 1, characterized in that: The anti-reflection structure design of the semiconductor laser chip (4) is achieved through at least one of the following methods: A light-reflecting structure is covered at the bottom of the light-emitting surface of the semiconductor laser chip (4); The bottom of the light-emitting surface of the semiconductor laser chip (4) is covered with a light-absorbing structure.

10. The anti-reflection semiconductor laser device according to claim 9, characterized in that: The light reflection structure covering the bottom of the light-emitting surface of the semiconductor laser chip (4) has optical diffuse reflection capability for its emission wavelength, and reflects the primary reflected light (8-2) reflected back to the side of the semiconductor laser chip (4) by the optical element to other directions, so as to prevent the secondary reflected light (8-3) from returning to the optical path again; the light absorption structure at the bottom of the light-emitting surface of the semiconductor laser chip (4) absorbs wavelengths that include its emission wavelength, and the higher the absorption rate, the better, so as to effectively absorb the primary reflected light (8-2) reflected back to the side of the semiconductor laser chip (4) by the optical element, thereby reducing the intensity of the secondary reflected light (8-3).

11. The anti-reflection semiconductor laser device according to claim 9, characterized in that: The light reflection structure covering the bottom of the light-emitting surface of the semiconductor laser chip (4) is a metal reflection layer, a semiconductor reflection layer, and a surface microstructure; the light absorption structure at the bottom of the light-emitting surface of the semiconductor laser chip (4) is a metal absorption layer and a semiconductor absorption layer; the metal reflection layer, semiconductor reflection layer, surface microstructure, metal absorption layer, and semiconductor absorption layer are prepared by vapor deposition and sputtering methods.

12. The anti-reflection semiconductor laser device according to claim 1, characterized in that: The cap (6) is a windowless cap or a transparent cap. The light window (6-2) of the transparent cap is coated with an anti-reflection film for the emission wavelength of the semiconductor laser chip. The anti-reflection film adopts the SiO2, TiO2, and Ta2O5 oxide optical film system.

13. The anti-reflection semiconductor laser device according to claim 1, characterized in that: The heat sink (3) is made of a high thermal conductivity material, including AlN, SiC, and diamond.

14. The anti-reflection semiconductor laser device according to claim 1, characterized in that: The tongue (2) and the base (1) are integrally formed or fixedly connected by welding or bonding. The heat sink (3) and the tongue (2), and the semiconductor laser chip (4) and the heat sink (3) are all fixedly bonded by AuSn alloy or thermally conductive adhesive.

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