Light and small optical fiber laser and air-cooling heat dissipation structure thereof

Abstract

A light and small optical fiber laser and an air cooling heat dissipation structure thereof relate to the technical field of optical fiber lasers, and the heat dissipation structure comprises a heat dissipation shell and a heat dissipation cavity cover plate which form a heat dissipation cavity; a mounting surface for mounting a pumping source is formed on the outer surface of the heat dissipation shell; an air inlet is formed in the heat dissipation cavity cover plate; an air outlet corresponding to the air inlet is formed in the side wall of the heat dissipation shell; the axial flow fan is axially perpendicular to the mounting surface and is arranged in the heat dissipation cavity, and a structure for feeding air from the air inlet is formed; the soaking layer is embedded in the mounting surface; the thermal conductivity of the soaking layer perpendicular to the thickness direction is greater than that of the soaking layer in the thickness direction; a plurality of groups of internal heat dissipation fins are arranged on the inner wall of the heat dissipation cavity corresponding to the area of the soaking layer and cover the air outlet side of the axial flow fan, the internal heat dissipation fins are arranged in an extending mode according to the air outlet track from the air inlet to the air outlet, and a flow guide channel extending from the air outlet side of the axial flow fan to the air outlet is formed between every two adjacent internal heat dissipation fins. The heat dissipation efficiency of the special-shaped space is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber lasers, in particular to a light and small fiber laser and a wind cooling heat dissipation structure thereof. BACKGROUND

[0002] In a multi-stage amplification small fiber laser system, a high-power pump source is usually required to achieve high-power output. These pump sources have a significant heat accumulation problem in the electro-optical conversion process. If the heat dissipation condition is not good, the operating temperature of the photoelectric devices inside the laser, especially the temperature-sensitive components, will generally rise, which will cause the output wavelength to drift away from the optimal absorption or amplification band of the gain fiber, reducing the output power and conversion efficiency of the laser. Therefore, in order to ensure the output performance of the fiber laser, heat dissipation needs to be performed on the heat concentration position of the fiber laser.

[0003] In related technologies, the heat dissipation schemes for fiber lasers are mainly divided into two categories: water cooling and air cooling. For the air cooling method, the general layout requires that the heat dissipation structure reserve sufficient height space in the direction perpendicular to the substrate to accommodate the fan itself and the tall fins that usually need to be matched with it, resulting in a large volume of the heat dissipation module, which is particularly not suitable for thin laser; and for laser housings with irregular shapes, the vertical air supply mode is difficult to effectively adapt to the complex irregular space form inside the housing, which is easy to form air flow dead angles or vortexes in the areas away from the fan, resulting in poor local heat dissipation. SUMMARY

[0004] The present application provides a light and small fiber laser and a wind cooling heat dissipation structure thereof, which solves the problem of efficient heat dissipation in an irregular space.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: In a first aspect, a wind cooling heat dissipation structure for a light and small fiber laser is provided, comprising: a heat dissipation shell with one open end and a heat dissipation cavity cover plate fixedly connected to the open end of the heat dissipation shell, forming a heat dissipation cavity; the closed end of the heat dissipation shell forms a mounting surface for mounting a pump source; at least one air inlet is formed in the heat dissipation cavity cover plate; at least one air outlet corresponding to the air inlet is formed in the side wall of the heat dissipation shell; axial flow fans corresponding to the air inlets are arranged in the heat dissipation cavity in a direction perpendicular to the mounting surface, and form a structure for air inlet from the air inlets; a heat equalization layer is embedded in the mounting surface; the heat equalization layer is configured as a thin layer structure, and its perpendicular to the thickness direction thermal conductivity is greater than the thickness direction thermal conductivity; The area of the inner wall of the heat dissipation cavity corresponding to the heat equalization layer is provided with a plurality of groups of internal heat dissipation fins ，And cover the axial flow fan out wind side, a plurality of groups of the internal heat dissipation fins are arranged according to the air outlet trajectory from the air inlet to the air outlet, and the adjacent internal heat dissipation fins form a flow guide channel extending from the axial flow fan out wind side to the air outlet.

[0006] Further, the said uniform heating layer is configured as a multi-layer graphite sheet, a uniform heating plate, or made of a high-thermal-conductivity metal matrix composite material.

[0007] Further, the peripheral side of the heat dissipation shell is further provided with external heat dissipation fins.

[0008] Further, the surface of the heat dissipation shell, the internal heat dissipation fins and / or the external heat dissipation fins is coated with a high-thermal-conductivity / high-radiation coating layer.

[0009] Further, the material of the heat dissipation shell and the cover plate is metal.

[0010] In a second aspect, a light and small optical fiber laser is provided, comprising the air-cooled heat dissipation structure for light and small optical fiber laser as described in the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A perspective view of the air-cooled heat dissipation structure for light and small optical fiber laser provided by the embodiment of the present application; Figure 2 A bottom view of the air-cooled heat dissipation structure for light and small optical fiber laser provided by the embodiment of the present application; Figure 3 A perspective view of the air-cooled heat dissipation structure for light and small optical fiber laser provided by the embodiment of the present application; Figure 2 A sectional view of A-A in the air-cooled heat dissipation structure for light and small optical fiber laser provided by the embodiment of the present application; Figure 4 A side view of the air-cooled heat dissipation structure for light and small optical fiber laser provided by the embodiment of the present application; Figure 5 A perspective view of the air-cooled heat dissipation structure for light and small optical fiber laser provided by the embodiment of the present application; Figure 4 A sectional view of B-B in the air-cooled heat dissipation structure for light and small optical fiber laser provided by the embodiment of the present application. DETAILED DESCRIPTION

[0012] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined purposes, the technical solutions in the embodiments of the present application are described clearly. Obviously, the described embodiments are some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0013] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification means at least one of the connected objects, and the character " / " generally means that the front and rear associated objects are in an "or" relationship.

[0014] The description of the method flow in the specification of the present application and the steps of the flowchart in the drawings of the present application are not necessarily strictly executed in the order of the steps, and the method steps can change the order of execution. Moreover, some steps can be omitted, a plurality of steps can be combined into one step for execution, and / or one step can be divided into a plurality of steps for execution.

[0015] There are basically two common heat dissipation methods for fiber lasers, namely water cooling and air cooling. Among them, the water cooling method is more common, and its principle is to tightly attach the heat dissipation surface that needs to be cooled to the water cooling plate of the internal water cooling pipeline, and through the water cooling box to circulate and control the temperature of the refrigerant and drive the refrigerant through the water cooling plate to efficiently cool the heat dissipation surface. However, due to the need for external water cooling box, the water cooling box has a large volume and high weight, which greatly reduces the overall integration of the laser, and is not suitable for some light and small applications with high requirements. At the same time, the maintenance cost is high for a long time, and there is a risk of leakage. The current air cooling structure often needs a heat dissipation space greater than the height of the long side of the fan and fins of the same height, which is suitable for larger cuboid lasers. For small lasers with height restrictions or other shapes of cross section including but not limited to circular, semicircular and irregular cylindrical shell lasers, this fan vertical placement cooling method often cannot meet the requirements, and the high height of the fins also increases the processing difficulty, which cannot meet the light and small requirements of the laser.

[0016] Based on this, in the present specification, a light and small air-cooled heat dissipation structure for fiber lasers is provided, which can adapt to different cross-sectional shapes and require smaller heat dissipation area height, to improve the integration of the heat dissipation structure, reduce maintenance cost and processing difficulty, and improve the working reliability of the fiber laser. At the same time, a corresponding fiber laser is involved, which will be described in detail one by one below in combination with the drawings and preferred embodiments.

[0017] Please refer to Figures 1-5 The embodiment of the present application provides a light and small air-cooled heat dissipation structure for fiber lasers, as shown in Figures 1-5 , comprising: An open heat dissipation shell 4 and a heat dissipation cavity 12 cover plate 5 fixedly connected to the open end of the heat dissipation shell 4 form a heat dissipation cavity 12; The outer surface of the closed end of the heat dissipation shell 4 forms a mounting surface 1 for mounting the pump source 2; At least one air inlet 8 is formed on the heat dissipation cavity 12 cover plate 5; The side wall of the heat dissipation shell 4 is provided with at least one air outlet 7 corresponding to the air inlet 8; The axial flow fan 10 corresponding to the air inlet 8 is axially perpendicular to the mounting surface, arranged in the heat dissipation cavity 12, and forms a structure for air inlet from the air inlet 8; The heat equalization layer 9 is embedded in the mounting surface 1; The heat equalization layer 9 is configured as a thin layer structure, and its perpendicular to the thickness direction thermal conductivity is greater than the thickness direction thermal conductivity; The inner wall of the heat dissipation cavity 12 is provided with a plurality of groups of internal heat dissipation fins 11 corresponding to the area of the heat equalization layer 9, and covers the air outlet side of the axial flow fan 10, a plurality of groups of the internal heat dissipation fins 11 are arranged according to the air outlet track from the air inlet 8 to the air outlet, and the adjacent internal heat dissipation fins 11 form a flow guide channel extending from the air outlet side of the axial flow fan 10 to the air outlet 7.

[0018] In the embodiment of the application, the axial flow fan is a fan in which gas flows along the axial direction of the fan; The heat dissipation fins guide the air outlet of the fan, so that the air outlet path is fixed without vortex, and the heat dissipation effect is enhanced. The axial flow fan takes in air from the cover plate air inlet, and after being guided by the heat dissipation fins, the air is taken out from one or more side wall air outlets of the heat dissipation cavity 12. Therefore, the overall heat dissipation cavity 12 takes in cold air from the bottom air inlet, carries away the heat generated by the pump through the heat dissipation fins, and then discharges the hot air through the air outlet, thereby achieving the heat dissipation effect.

[0019] By using the above technical solution, the heat equalization layer embedded in the mounting surface of the heat dissipation shell is used to realize ultra-low thermal resistance transmission from the pump heat source to the heat dissipation fin; The directional guidance of the fin to the airflow is combined to realize the improvement of the uniform temperature performance, the heat equalization layer reduces the local temperature difference control of the mounting surface, effectively avoiding the wavelength drift and device failure of the pump device caused by heat concentration; The shaped fin eliminates airflow vortex, so that the contact area of cold air and fin is greatly increased, and the heat dissipation flux density is significantly improved compared with traditional air cooling.

[0020] The pump of the optical fiber laser installed with the heat dissipation structure is mounted to the mounting surface. When the pump generates heat, the heat generated by the pump is transmitted to the heat dissipation shell. Since the heat equalization layer inside the shell has a very high transverse thermal conductivity (referring to the heat conduction ability perpendicular to the thickness direction (i.e. in the plane), which is opposite to the longitudinal thermal conductivity), the heat can be quickly conducted to the heat dissipation fins distributed on the bottom surface of the heat dissipation shell through the heat equalization layer. When a certain pump device generates heat and causes the local temperature of the heat dissipation shell to rise, the heat can be quickly equalized, effectively avoiding the device failure caused by the excessive local temperature.

[0021] Subsequently, the air pressure generated by the fan causes the cold air outside the heat dissipation shell to enter the heat dissipation cavity 12 quickly through the air inlet, and to flow along the expected trajectory through the guidance of the heat dissipation fins, in the process, the fins heat is taken away to cool the heat dissipation shell efficiently, and finally the air in the heat dissipation cavity 12 is discharged from the heat dissipation shell through the air outlet, so as to realize rapid cooling of the pumping device.

[0022] In the implementation process, the air outlet position is configured according to the specific shape of the heat dissipation area, so as to design a reasonable air outlet path. The topology structure of the internal heat dissipation fin can be optimized by fluid dynamics simulation, and the flow guide channel can be constructed in a straight line, a wave shape, a bifurcated shape, and / or a tapered / expanded flow channel, etc., so as to further improve the heat dissipation efficiency and uniformity. The height, thickness, and spacing of the fin can also be adaptively optimized, and the fin curvature, spacing, and flow guide characteristics are designed to match the internal space constraints (such as circular / abnormal cross-section) of the shell, so as to build an efficient straight flow guide channel without airflow separation points, ensure that the heat dissipation performance is not limited by the shape of the shell, and provide a universal heat dissipation solution for laser devices with abnormal shells. The performance degradation problem caused by space adaptation in traditional solutions is completely solved, and a universal heat dissipation solution is provided for various laser devices with abnormal shells. Since the heat dissipation fins are arranged according to the air outlet path, the cold air entering the heat dissipation cavity from the fan is guided, so that the cold air forms a high-speed cold air flow without vortex in the heat dissipation cavity, and the contact area between the cold air and the heat dissipation fins is greatly increased. In the working process of the heat dissipation system, the cold air entering the heat dissipation cavity from the fan can take away a large amount of heat conducted to the fins by the pumping device, further improving the heat dissipation capacity of the heat dissipation shell, and ensuring the working reliability of the fiber laser.

[0023] Further, the heat equalization layer 9 is configured as a multi-layer graphite sheet, a heat spreader, or a high-thermal-conductivity metal matrix composite material, etc. with excellent lateral thermal conductivity. It is combined with the internal space of the top (closed end) of the heat dissipation shell 4 through welding or brazing process; its thickness and area can be adjusted according to the thermal load. Since the heat equalization layer is a multi-layer graphite structure with extremely high lateral thermal conductivity and is welded inside the mounting surface of the heat dissipation shell, the lateral thermal conductivity of the mounting surface is greatly improved, so that when a certain part or multiple parts of the mounting surface are heated, the heat equalization layer can quickly transfer the heat to other positions of the heat dissipation shell, to improve the heat dissipation effect of the pump, prevent local temperature from being too high, and make the pump work at an appropriate temperature, thereby ensuring the working reliability of the fiber laser. A good heat equalization layer material combines the light weight of aluminum and the high thermal conductivity of copper, and can more efficiently conduct and diffuse the heat of the pump source laterally to the entire heat dissipation area, significantly improving the heat transfer efficiency compared to a pure aluminum base.

[0024] Further, the peripheral side of the heat dissipation shell 4 is also provided with external heat dissipation fins 6. The form of the external heat dissipation fins can be diversified, such as needle-shaped, strip-shaped, scale-shaped, and auxiliary heat dissipation measures such as heat-conducting paste and thermoelectric cooler TEC can be considered to be integrated under the local hot spot.

[0025] Further, the surface of the heat dissipation shell 4, the internal heat dissipation fins 11 and / or the surface of the external heat dissipation fins 6 can be coated with a high-thermal-conductivity / high-radiation coating, such as a ceramic thermal-conductivity coating or an anodized layer, to improve its heat radiation and conduction ability to the air.

[0026] Further, the axial flow fan 10 is 2, arranged in parallel. The axial flow fan 10 is horizontally installed on the inner side of the heat dissipation cavity 12 cover plate 5 (i.e. inside the heat dissipation cavity 12) through a support or buckle, and its air inlet is opposite to the air inlet 8 on the heat dissipation cavity 12 cover plate 5, and the air outlet side faces the starting area of the internal heat dissipation fins 10. The fan can adopt different sizes, air volume and air pressure to adapt to the heat dissipation needs of different power pump sources.

[0027] Further, the materials of the heat dissipation shell 4 and the heat dissipation cavity 12 cover plate 5 are preferably metals with good thermal conductivity, such as aluminum alloy, copper alloy or composite material. The connection mode of the shell and the cover plate can adopt screw fastening, or buckle, welding or other reliable sealing modes with a certain degree of sealing. The shape of the heat dissipation cavity 12 is completely determined by the shape of the shell and the cover plate, which can be a flat rectangular body, a flat cylinder, a fan-shaped or other special-shaped space suitable for the shell.

[0028] Further, the heat dissipation cavity 12 cover plate 5 is provided with a wire hole.

[0029] Compared with the water cooling system, the embodiment of the present application adopts a full-air-cooled heat dissipation structure, completely avoiding the risk of sealing failure and electrical short circuit caused by liquid circulation of the water cooling system. The water cooling tank and the circulation pipeline are cancelled, the maintenance frequency caused by scaling and corrosion is reduced, and the operation and maintenance cost in the expected service life is reduced. At the same time, the integrated heat dissipation shell directly bears the pumping device, reduces the number of heat transfer interfaces, reduces the interface thermal resistance, and shortens the thermal response time.

[0030] Corresponding to the above-mentioned air-cooled heat dissipation structure for light and small optical fiber lasers, the embodiment of the present application provides a light and small optical fiber laser comprising the above-mentioned air-cooled heat dissipation structure for light and small optical fiber lasers.

[0031] The above-mentioned light and small optical fiber laser realizes the same technical effects as the above-mentioned air-cooled heat dissipation structure embodiment, and details are not repeated here to avoid repetition.

[0032] It should be noted that, in the present document, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a", "comprising", or "includes a", does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus of the present embodiments are not limited by the order of the steps or the sequences of the steps, as some steps can occur simultaneously, in other sequences, or in other embodiments, the steps can be eliminated or combined. Also, features described in relation to one example can be combined in other examples.

[0033] It is to be understood that the embodiments of the present application described above are merely illustrative and that various modifications can be made by those skilled in the art without departing from the spirit and scope of the present application. In addition, the features and embodiments described in relation to one example can be combined in other examples.

Claims

1. A lightweight, compact fiber laser air-cooled heat dissipation structure, characterized in that, include: A heat dissipation shell with one open end and a heat dissipation cavity cover plate fixedly connected to the open end of the heat dissipation shell form a heat dissipation cavity; the outer surface of the closed end of the heat dissipation shell forms a mounting surface for installing a pump source; at least one air inlet is provided on the heat dissipation cavity cover plate; at least one air outlet is provided on the side wall of the heat dissipation shell corresponding to the air inlet. An axial flow fan, corresponding to each of the air inlets, is disposed in the heat dissipation cavity with its axis perpendicular to the mounting surface, and forms a structure that allows air to enter from the air inlets. A heat-spreading layer is embedded in the mounting surface; the heat-spreading layer is configured as a thin layer structure, and its thermal conductivity perpendicular to the thickness direction is greater than its thermal conductivity in the thickness direction. The inner wall of the heat dissipation cavity is provided with multiple sets of internal heat dissipation fins corresponding to the area of ​​the heat dissipation layer, and covers the air outlet side of the axial flow fan. The multiple sets of internal heat dissipation fins are arranged to extend according to the air outlet trajectory from the air inlet to the air outlet, and a guide channel extending from the air outlet side of the axial flow fan to the air outlet is formed between adjacent internal heat dissipation fins.

2. The air-cooled heat dissipation structure for lightweight fiber lasers according to claim 1, characterized in that, The heat spreader is configured as a multilayer graphite sheet, a heat spreader plate, or a high thermal conductivity metal matrix composite material.

3. The air-cooled heat dissipation structure for lightweight fiber lasers according to claim 1, characterized in that, The heat dissipation shell is also provided with external heat dissipation fins on its periphery.

4. The air-cooled heat dissipation structure for lightweight fiber lasers according to claim 1, characterized in that, The outer surface of the heat sink housing, the inner heat sink fins and / or the surface of the outer heat sink fins are coated with a high thermal conductivity / high radiation coating.

5. The air-cooled heat dissipation structure for a lightweight fiber laser according to claim 1, characterized in that, The heat sink housing and cover are made of metal.

6. A lightweight fiber laser, characterized in that, Includes a heat dissipation structure for lightweight fiber lasers as described in any one of claims 1-5.

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