A lightweight and high-power pump source

Abstract

The present invention relates to a lightweight, high-power pump source, comprising a housing and N groups of pump light chips installed in the housing in separate sections, where N is an integer greater than or equal to 1. Each group of pump light chips comprises a corresponding coupling mirror group, and each group of pump light chips is used to emit pump lasers of different wavelengths. After beam shaping is performed by the corresponding coupling mirror group, the pump lasers are coupled to an output optical fiber via an output mirror group. The housing is made of a graphene-reinforced aluminum-based composite material. The present invention uses lightweight materials to make the packaging housing, which, on the one hand, maintains excellent mechanical properties and stability, and, on the other hand, has a density much lower than that of oxygen-free copper, thereby effectively reducing the weight of the pump source per unit power, making the entire fiber laser system lighter and easier to install and maintain. At the same time, the present invention introduces multi-wavelength pump light chips, optimizes the wavelength distribution of the pump light, makes it more consistent with the absorption characteristics of the ytterbium-doped optical fiber, effectively disperses the heat load of the ytterbium-doped optical fiber, and significantly increases the threshold of the mode instability effect, thereby improving the power output capacity and long-term operation stability of the fiber laser system.

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] Currently, the pump sources used in fiber laser systems are often encapsulated in oxygen-free copper. While this housing exhibits minimal deformation under ambient temperature fluctuations and external stresses, ensuring the stability and precision of the pump source's internal components, it also carries a significant disadvantage: the overall pump source is heavy. As a crucial component of a fiber laser system, the weight of the pump source not only affects the system's portability and flexibility but also increases the difficulty of installation and maintenance. This fails to meet the current industrial demand 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 ytterbium-doped fiber and has high absorption efficiency, due to the large absorption coefficient of ytterbium-doped fiber, when the pump power is high, it will cause a large thermal load on the gain fiber. This high thermal 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 address the above problems, the present invention provides a lightweight, 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 objectives, the present invention provides a lightweight, high-power pump source, comprising a housing and N groups of pump optical chips installed in the housing in separate sections, where N is an integer greater than or equal to 1. Each group of pump optical chips includes a corresponding coupling mirror group. Each group of pump optical chips is used to emit pump lasers of different wavelengths and, after beam shaping through the corresponding coupling mirror group, is coupled to an output optical fiber through an output mirror group. The housing is made of a 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, and the slow-axis collimator is used to collimate the pump laser in the direction of a smaller divergence angle. The planes where the larger divergence angle and the smaller divergence angle are located are 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. Each dichroic mirror receives 2-4 groups of pump lasers of different wavelengths, combines them and then transmits them to the filter and the output lens in sequence.

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

[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 to 1000 nm.

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

[0014] In one specific embodiment, the 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 specific embodiment, the mirror bodies of the coupling mirror assembly and / or the output mirror assembly are welded to the housing by spot melting of metal copper by nanosecond large pulse laser.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention provides a lightweight, high-power pump source, which uses a specific lightweight material to make a packaging shell. It not only maintains excellent mechanical properties and stability, but also can maintain a small deformation under ambient temperature changes and external stress, ensuring the precise arrangement and long-term reliability of the internal components of the pump source. More importantly, its low density effectively reduces the weight of the pump source per 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

[0018] Figure 1 This is a schematic structural diagram of a lightweight and high-power pump source of the present invention.

[0019] 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.

[0020] Figure 3 This is a schematic diagram of the structure of the coupling lens assembly or the output lens assembly after being welded to the housing. DETAILED DESCRIPTION

[0021] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0023] 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 sections, where N is an integer greater than or equal to 1. Each pump light chip in each group includes 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, is coupled to an output optical fiber (not shown in the figure) through an output mirror group 40. The housing 10 is made of a graphene-reinforced aluminum-based composite material. The housing processed by the graphene-reinforced aluminum-based composite material 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 is kept small under the action of oxygen-free copper, 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, thereby effectively reducing the weight of the pump source per unit power. This improvement makes the entire fiber laser system lighter and easier to install and maintain, greatly meeting the urgent demand of the industrial field for lightweight high-power laser systems. 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 to make 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.

[0024] 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.

[0025] 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 the direction of 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 the direction of 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. After collimation, the pump laser is The pump laser light is then adjusted at its transmission angle by the reflector 302 so that it can be accurately transmitted to the output mirror assembly downstream in the optical path. It is understood that after each laser diode chip emits the pump laser light, it is collimated by its corresponding fast-axis collimator and slow-axis collimator 301, and then adjusted at its transmission angle by its corresponding reflector 302 before it is finally transmitted to the output mirror assembly 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 light emitted by the same echelon of the M laser diodes arranged in the same area, and adjust the angle so that each received pump laser light beam is effectively transmitted to the output mirror assembly 40. The focal lengths of the fast-axis collimator and slow-axis collimator corresponding to each group of laser diode chips vary according to the wavelength of the pump laser light emitted by the laser diode chips. The adjustment reflector 50 corresponding to each group of laser diode chips is coated with a corresponding reflective coating according to the different wavelengths of the pump laser light to improve reflection efficiency.

[0026] In one specific embodiment, the output mirror assembly 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 of different wavelengths, combines them, 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 transmit, 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 power density and a smaller spot size.

[0027] In one specific embodiment, the inner surface of the shell 10 is coated 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 during high-power operation. The heat dissipation layer is made of a high-thermal-conductivity metal film layer and can effectively transfer heat from the pump chip to the shell.

[0028] In one specific embodiment, the pump lasers of different wavelengths emitted by each or every two groups of pump optical chips are all within the absorption band of the ytterbium-doped gain medium and can be effectively absorbed by the gain medium, resulting in population inversion. The wavelength of the laser light emitted by each group of pump optical chips is within the range of 900nm-1000nm. For example, the pump laser light emitted by the first group of pump optical chips 201 and the second group of pump optical chips 202 has a wavelength of 915nm, and the pump laser light emitted by the third group of pump optical chips 203 and the fourth group of pump optical chips 204 has a wavelength of 976nm. It is understood that the fifth and sixth groups of pump laser chips can also be configured to emit laser light 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 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 capability and long-term operational stability of the fiber laser system.

[0029] In one specific embodiment, the output mirror assembly 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 assemblies 403, pump lasers of different wavelengths will be focused onto the same focal point, ensuring that the pump laser is coupled to the output optical fiber with high energy density and a small spot size.

[0030] like Figure 2-Figure 3 As shown, in one specific embodiment, the side surfaces of the coupling mirror group 30 and / or the output mirror group 40 include a metallized deposition layer to facilitate welding installation. The metallized deposition layer includes an adhesive layer 601, a barrier layer 602, and a welding layer 603 formed using 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 diffusion of the welding layer metal. The welding layer 603 is used to improve the wettability of the deposited metal, so that the solder 60 can be melted at a specific 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.

[0031] 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 exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description. It is intended that all changes that fall within the meaning and range of equivalents of the claims be included in the present invention, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0032] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A lightweight, high-power pump source, characterized by: The invention comprises a housing and N groups of pump light chips installed in the housing in separate sections, where 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 by the corresponding coupling mirror group, couple the beams to the output optical fiber via the output mirror group. The coupling mirror group comprises 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 planes containing the larger divergence angle and the smaller divergence angle are rotated 90 degrees with the laser propagation direction as the axis. The reflector is used to adjust the transmission angle of the pump laser. 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. The reflector adjusts the transmission angle of the pump laser until the pump laser is finally transmitted to the output mirror group. An adjustment reflector corresponding to each group of pump light chips is further provided. The adjustment reflector is used to receive the pump lasers emitted by the M laser diodes in the same echelon and adjust the angle so that each received beam of pump laser is effectively transmitted to the output mirror group. The output mirror group includes N-1 dichroic mirrors, filters, and output lenses. Each dichroic mirror receives 2-4 groups of pump lasers of different wavelengths, combines them, and then transmits them to the filters and output lenses in sequence. Each dichroic mirror can reflect lasers of a specific wavelength while allowing lasers of other wavelengths to transmit, thereby achieving beam combining of multi-wavelength pump lasers. The filters 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 and transmitted to the output fiber. The shell is made of graphene-reinforced aluminum-based composite material.

2. 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.

3. 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.

4. The lightweight, high-power pump source according to claim 3, characterized in that: The wavelength of the laser emitted by each group of pump light chips is within 900nm-1000nm.

5. 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.

6. The lightweight, high-power pump source according to claim 1, characterized in that: The side surfaces of the mirror bodies 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 using titanium, platinum and gold.

7. The lightweight, high-power pump source according to claim 6, characterized in that: The mirror bodies of the coupling mirror group and / or the output mirror group are welded to the housing by spot-melting metal copper with a nanosecond large pulse laser.

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