Lightweight high-power pumping source

Abstract

The invention relates to a light-weight high-power pumping source which comprises a shell and N sets of pumping light chips installed in the shell in a partitioned mode, N is an integer larger than or equal to 1, and each set of pumping light chips comprises a corresponding coupling mirror set. Each group of pump light chips is used for emitting pump laser with different wavelengths, the pump laser is subjected to beam shaping through the respective corresponding coupling mirror group and then is coupled to the output optical fiber through the output mirror group, and the shell is made of a graphene reinforced aluminum-based composite material. On one hand, excellent mechanical performance and stability are kept, and on the other hand, the density of the fiber laser is far lower than that of oxygen-free copper, so that the weight of a pumping source under unit power is effectively reduced, and the whole fiber laser system is lighter and easier to install and maintain; meanwhile, the multi-wavelength pump light chip is introduced, the wavelength distribution of the pump light is optimized, the pump light is made to better conform to the absorption characteristic of the ytterbium-doped optical fiber, the thermal load of the ytterbium-doped optical fiber is effectively dispersed, the threshold value of the mode instability effect is remarkably increased, and therefore the power output capacity and the long-term operation stability of an optical fiber laser system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pump sources, and in particular to a lightweight and high-power pump source. Background Art

[0002] At present, the pump sources used in fiber laser systems are mostly made of oxygen-free copper packaging shells. Although the shell has the characteristic of small deformation under ambient temperature changes and external stress, ensuring the stability and precision of the internal components of the pump source, it also brings significant disadvantages, that is, the entire pump source is heavy. As an important part of the fiber laser system, the weight of the pump source not only affects the portability and flexibility of the entire system, but also increases the difficulty of installation and maintenance, and cannot meet the urgent demand of current industrial development for lightweight high-power fiber laser systems.

[0003] In addition, current fiber laser systems generally use a single 976nm pump source. Although the 976nm pump light matches the absorption peak of the ytterbium-doped fiber and has a high absorption efficiency, the absorption coefficient of the ytterbium-doped fiber is large. When the pump power is high, it will cause a large heat load on the gain fiber. This high heat load can easily cause mode instability effects, thereby limiting the further increase in the power of the fiber laser system. Therefore, fiber laser systems using a single 976nm pump source face great challenges in achieving high-power laser output.

[0004] Therefore, there is an urgent need in this field to solve the technical problems of heavy weight and low power of fiber laser systems. Summary of the invention

[0005] Based on this, in order to solve the above problems, the present invention provides a lightweight and high-power pump source, which not only reduces the weight of the pump source, but also improves the power output capacity and long-term operation stability of the fiber laser system.

[0006] To achieve the above-mentioned purpose, the present invention provides a lightweight high-power pump source, comprising a shell and N groups of pump light chips installed in the shell in separate areas, N is an integer greater than or equal to 1, each group of pump light chips comprises a corresponding coupling mirror group, each group of pump light chips is used to emit pump lasers of different wavelengths and after beam shaping through the corresponding coupling mirror group, the beams are coupled to the output optical fiber through the output mirror group, and the shell is made of graphene-reinforced aluminum-based composite material.

[0007] In one specific embodiment, each group of pump light chips includes M laser diode chips, where M is an integer greater than or equal to 1, and the laser diode chips in the same group are arranged in a stepped manner and installed in the same area of ​​the housing.

[0008] In one specific embodiment, the coupling mirror group includes a fast-axis collimator, a slow-axis collimator and a reflector arranged along the optical path, the fast-axis collimator is used to collimate the pump laser in the direction of a larger divergence angle, the slow-axis collimator is used to collimate the pump laser in the direction of a smaller divergence angle, the plane where the larger divergence angle and the smaller divergence angle are located is rotated 90° with the laser propagation direction as the axis, and the reflector is used to adjust the transmission angle of the pump laser.

[0009] In one specific embodiment, the output mirror group includes N-1 dichroic mirrors, a filter and an output lens, and each dichroic mirror receives 2-4 groups of pump lasers of different wavelengths for beam combination and then transmits them to the filter and the output lens in sequence.

[0010] In one specific embodiment, a heat dissipation layer is plated on the inner surface of the housing.

[0011] In one specific embodiment, the pump lasers of different wavelengths emitted by each group of pump optical chips are all located within the absorption band of the ytterbium-doped gain medium.

[0012] In one specific embodiment, the wavelength of the laser emitted by each group of pump optical chips is within the range of 900 nm-1000 nm.

[0013] In one specific embodiment, the output lens group has an achromatic focusing function and can be a doublet lens, an aspherical achromatic lens or a triplet achromatic lens.

[0014] In one specific embodiment, the mirror body side surfaces of the coupling mirror assembly and / or the output mirror assembly include a metallized deposition layer, and the metallized deposition layer includes an adhesive layer, a barrier layer and a welding layer formed using titanium, platinum and gold.

[0015] In one of the specific embodiments, the mirror bodies of the coupling mirror assembly and / or the output mirror assembly are welded to the shell by spot melting of metal copper using a nanosecond large pulse laser.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a lightweight high-power pump source, which adopts a specific lightweight material to make a packaging shell, which not only maintains excellent mechanical properties and stability, but also can maintain a small deformation under environmental temperature changes and external stress, ensuring the precise arrangement and long-term reliability of the internal components of the pump source. More importantly, its density is low, thereby effectively reducing the weight of the pump source under unit power, making the entire fiber laser system lighter, easier to install and maintain, and greatly meeting the urgent demand for lightweight high-power laser systems in the industrial field; at the same time, the present invention introduces a multi-wavelength pump light source, which not only optimizes the wavelength distribution of the pump light, making it more consistent with the absorption characteristics of the ytterbium-doped optical fiber, but also effectively disperses the heat load of the ytterbium-doped optical fiber, significantly increasing the threshold of the mode instability effect, thereby effectively improving the power output capacity and long-term operation stability of the fiber laser system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The schematic diagram is a structural diagram of a lightweight and high-power pump source of the present invention.

[0018] Figure 2 It is a schematic diagram of the structure of the coupling mirror group or the output mirror group after metallization of the present invention.

[0019] Figure 3 It is a schematic diagram of the structure after the coupling mirror assembly or the output mirror assembly of the present invention is welded to the housing. DETAILED DESCRIPTION

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0021] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] like Figure 1As shown, this embodiment provides a lightweight high-power pump source, including a housing 10 and N groups of pump light chips 20 installed in the housing 10 in separate areas, N being an integer greater than or equal to 1, each pump light chip in each group comprises a corresponding coupling mirror group 30, each group of pump light chips is used to emit pump lasers of different wavelengths and after beam shaping by the corresponding coupling mirror group 30, the beams are coupled to output optical fibers (not shown in the figure) through an output mirror group 40, the housing 10 is made of graphene-enhanced aluminum-based composite materials, and the housing processed by the graphene-enhanced aluminum-based composite materials has the characteristics of low density, high thermal conductivity and high rigidity, so that the housing 10 not only maintains excellent mechanical properties and stability, but also can withstand changes in ambient temperature and external stress. The deformation amount is kept small under the action, which ensures the precise arrangement and long-term reliability of the internal components of the pump source. More importantly, its density is much lower than that of oxygen-free copper, which effectively reduces the weight of the pump source under unit power. This improvement makes the entire fiber laser system lighter, easier to install and maintain, and greatly meets the urgent demand for lightweight high-power laser systems in the industrial field. At the same time, the lightweight and high-power pump source provided by this embodiment introduces a multi-wavelength pump chip, which not only optimizes the wavelength distribution of the pump light, making it more consistent with the absorption characteristics of the ytterbium-doped fiber, but also effectively disperses the heat load of the ytterbium-doped fiber, significantly increasing the threshold of the mode instability effect, thereby improving the power output capacity and long-term operation stability of the fiber laser system.

[0023] In one specific embodiment, each group of pump light chips includes M laser diode chips, where M is an integer greater than or equal to 1. The laser diode chips in the same group are arranged in a stepped manner and installed in the same area of ​​the housing 10, ensuring effective use of space while ensuring that each laser diode chip can effectively emit pump laser and transmit it downstream.

[0024] In one specific embodiment, the coupling mirror group 30 includes a fast-axis collimator (attached to the laser diode chip), a slow-axis collimator 301 and a reflector 302 arranged along the optical path. After the pump laser is emitted from the laser diode chip, it first passes through the fast-axis collimator and the slow-axis collimator 301. The fast-axis collimator is used to collimate the pump laser in a direction with a larger divergence angle (usually parallel to the PN junction direction), and the slow-axis collimator 301 is used to collimate the pump laser in a direction with a smaller divergence angle (usually perpendicular to the PN junction direction). The fast-axis collimator and the slow-axis collimator 301 work together to ensure that the pump laser maintains a high collimation characteristic during transmission. The pump laser is then adjusted to have its transmission angle adjusted by the reflector 302 so that it can be accurately transmitted to the output mirror group downstream of the optical path. It can be understood that after each laser diode chip emits the pump laser, it is collimated by the corresponding fast-axis collimator and slow-axis collimator 301, and the transmission angle is adjusted by the corresponding reflector 302 before it is finally transmitted to the output mirror group 40. An adjustment reflector 50 corresponding to each group of laser diode chips is also provided. The adjustment reflector 50 is used to receive the pump laser emitted by the same echelon of the M laser diodes that are step-set in the same area, and adjust the angle so that each received pump laser is effectively transmitted to the output mirror group 40. The focal lengths of the fast-axis collimator and slow-axis collimator corresponding to each group of laser diode chips are different according to the wavelength of the pump laser emitted by the laser diode chip, and the adjustment reflector 50 corresponding to each group of laser diode chips is coated with a corresponding reflective film according to the different wavelengths of the pump laser to improve the reflection efficiency.

[0025] In one specific embodiment, the output mirror group 40 includes N-1 dichroic mirrors 401, a filter 402 and an output lens 403. Each dichroic mirror 401 receives 2-4 groups of pump lasers with different wavelengths for beam combining and then transmits them to the filter 402 and the output lens 403 in sequence. Each dichroic mirror 401 can reflect lasers of a specific wavelength while allowing lasers of other wavelengths to be transmitted, thereby achieving beam combining of multi-wavelength pump lasers. The filter 402 can prevent stray light in the fiber laser system from being reflected back to the pump source and damaging the pump chip. Finally, the pump laser is focused by the output lens 403 and transmitted to the output optical fiber with a higher energy density and a smaller spot size.

[0026] In one specific embodiment, the inner surface of the shell 10 is plated with a heat dissipation layer to enhance the heat dissipation capacity of the shell 10 and ensure the stability and reliability of the pump source when operating at high power. The heat dissipation layer is made of a high thermal conductivity metal film layer and can effectively conduct heat from the pump chip to the shell.

[0027] In one specific embodiment, the pump lasers of different wavelengths emitted by each group or every two groups of pump optical chips are all located in the absorption band of the ytterbium-doped ion gain medium, and can be effectively absorbed by the gain medium to form a population inversion. The wavelength of the laser emitted by each group of pump optical chips is located within 900nm-1000nm. For example, the wavelength of the pump laser emitted by the first group of pump optical chips 201 and the second group of pump optical chips 202 is 915nm, and the wavelength of the pump laser emitted by the third group of pump optical chips 203 and the fourth group of pump optical chips 204 is 976nm. It can be understood that the fifth group and the sixth group of pump laser chips can also be set to emit lasers with a wavelength of 940nm. This multi-wavelength pumping not only optimizes the wavelength distribution of the pump light, making it more consistent with the absorption characteristics of the ytterbium-doped optical fiber, but also effectively disperses the heat load of the ytterbium-doped optical fiber, significantly increases the threshold of the mode instability effect, and thus improves the power output capacity and long-term operation stability of the fiber laser system.

[0028] In one specific embodiment, the output mirror group 403 has an achromatic focusing function and can be a doublet lens, an aspheric achromatic lens, a triplet achromatic lens, etc. When the pump laser passes through these output mirror groups 403, the pump lasers of different wavelengths will be focused on the same focal point, ensuring that the pump laser is coupled to the output optical fiber with high energy density and small spot size.

[0029] like Figure 2-Figure 3 As shown, in one specific embodiment, the mirror body side surfaces of the coupling mirror group 30 and / or the output mirror group 40 all include a metallized deposition layer for easy welding installation. The metallized deposition layer includes an adhesive layer 601, a barrier layer 602 and a welding layer 603 formed by titanium, platinum and gold. The adhesive layer 601 is used to improve the adhesion of the deposited metal to ensure that the deposited layer can be firmly attached to the mirror body. The barrier layer 602 is used to prevent the metal of the welding layer from diffusing. The welding layer 603 is used to improve the wettability of the deposited metal, so that the solder 60 can be melted at a fixed point under the action of a nanosecond large pulse laser and achieve a high-strength connection with the shell, thereby ensuring a firm connection between the mirror body and the shell and improving the stability and reliability of the pump source. The solder can be made of copper, silver, tin, etc.

[0030] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0031] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A lightweight high-power pump source, characterized in that: It comprises a shell and N groups of pump light chips which are installed in the shell in separate sections, N is an integer greater than or equal to 1, each group of pump light chips comprises a corresponding coupling mirror group, each group of pump light chips is used to emit pump lasers of different wavelengths and after beam shaping through the corresponding coupling mirror group, they are coupled to the output optical fiber through the output mirror group, and the shell is made of graphene-reinforced aluminum-based composite material.

2. A lightweight high-power pump source according to claim 1, characterized in that: Each group of pump light chips includes M laser diode chips, where M is an integer greater than or equal to 1, and the laser diode chips in the same group are arranged in a stepped manner and installed in the same area of ​​the housing.

3. A lightweight high-power pump source according to claim 1, characterized in that: The coupling mirror group includes a fast-axis collimator, a slow-axis collimator and a reflector arranged along the optical path. The fast-axis collimator is used to collimate the pump laser in the direction of a larger divergence angle, and the slow-axis collimator is used to collimate the pump laser in the direction of a smaller divergence angle. The plane where the larger divergence angle and the smaller divergence angle are located is rotated 90° with the laser propagation direction as the axis, and the reflector is used to adjust the transmission angle of the pump laser.

4. A lightweight high-power pump source according to claim 3, characterized in that: The output mirror group includes N-1 dichroic mirrors, a filter and an output lens. Each dichroic mirror receives 2-4 groups of pump lasers with different wavelengths, combines them and transmits them to the filter and the output lens in sequence.

5. The lightweight high-power pump source according to claim 1, characterized in that: The inner surface of the shell is plated with a heat dissipation layer.

6. The lightweight high-power pump source according to claim 1, characterized in that: The pump lasers of different wavelengths emitted by each group of pump optical chips are all located within the absorption band of the ytterbium-doped gain medium.

7. A lightweight high-power pump source according to claim 6, characterized in that: The wavelength of the laser emitted by each group of pump light chips is within 900nm-1000nm.

8. The lightweight high-power pump source according to claim 1, characterized in that: The output lens group has an achromatic focusing function and can be a doublet lens, an aspherical achromatic lens or a triplet achromatic lens.

9. The lightweight high-power pump source according to claim 1, characterized in that: The mirror body side surfaces of the coupling mirror assembly and / or the output mirror assembly all include a metallized deposition layer, and the metallized deposition layer includes an adhesive layer, a barrier layer and a welding layer formed by using titanium, platinum and gold.

10. A lightweight high-power pump source according to claim 9, characterized in that: The mirror bodies of the coupling mirror group and / or the output mirror group are welded to the shell by spot melting of metal copper by nanosecond large pulse laser.

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