Lightweight high-power pump source

Abstract

The present invention relates to a lightweight high-power pump source, comprising a housing and N pump light chips installed in partitions in the housing, wherein N is an integer greater than or equal to 1, each pump light chip comprises a respective corresponding coupling lens group, and each pump light chip is used for emitting pump laser light with different wavelengths, performing beam shaping by means of the respective corresponding coupling lens group, and then coupling the pump laser light to an output optical fiber by means of an output lens group; and the housing is made of a graphene-reinforced aluminum matrix composite material. In the present invention, a lightweight material is used to manufacture a package housing, and therefore excellent mechanical properties and stability are maintained. Since the density of the lightweight material is much lower than that of oxygen-free copper, the weight of the pump source per unit power is effectively reduced, thereby making the entire optical-fiber laser system more lightweight, and thus facilitating installation and maintenance. Moreover, the present invention introduces multi-wavelength pump light chips to optimize the wavelength distribution of pump light, thereby making the pump light better match the absorption characteristics of ytterbium-doped optical fibers, and thus effectively redistributing the thermal load of the ytterbium-doped optical fibers and significantly increasing the threshold value of a mode instability effect, thus improving the power output capability and long-term operation stability of the optical-fiber laser system.

Description

A lightweight, high-power pump source Technical Field

[0001] This invention relates to the field of pump source technology, and more specifically, to a lightweight, high-power pump source. Background Technology

[0002] Currently, pump sources used in fiber laser systems are mostly encapsulated in oxygen-free copper. While this housing exhibits minimal deformation under environmental temperature changes and external stress, ensuring the stability and precision of the internal components, it also introduces a significant drawback: a substantial weight for the entire pump source. As a crucial component of fiber laser systems, the pump source's weight not only affects the system's portability and flexibility but also increases the difficulty of installation and maintenance, failing to meet the urgent industrial demand for lightweight high-power fiber laser systems.

[0003] Furthermore, current fiber laser systems generally employ a single 976nm pump source. Although the 976nm pump light matches the absorption peak of ytterbium-doped fiber and has high absorption efficiency, the large absorption coefficient of ytterbium-doped fiber leads to a large thermal load on the gain fiber when the pump power is high. This high thermal load can easily cause mode instability, thus limiting the further increase in the power of the fiber laser system. Therefore, fiber laser systems using a single 976nm pump source face significant challenges in achieving high-power laser output.

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

[0005] In view of this, and to address the above problems, the present invention provides a lightweight, high-power pump source that not only reduces the weight of the pump source but also improves the power output capability and long-term operational 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 partitioned and installed within the housing, where N is an integer greater than or equal to 1. Each group of pump optical chips includes its own corresponding coupling mirror group. Each group of pump optical chips is used to emit pump lasers of different wavelengths, which are then shaped by their respective coupling mirror groups and coupled to the output optical fiber via the output mirror group. The housing 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 collimating mirror, a slow-axis collimating mirror, and a reflecting mirror arranged along the optical path. The fast-axis collimating mirror is used to collimate the pump laser in the direction of a larger divergence angle, and the slow-axis collimating mirror is used to collimate the pump laser in the direction of a smaller divergence angle. The planes containing the larger and smaller divergence angles are rotated 90° about the laser propagation direction. The reflecting mirror 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, filters, and output lenses. Each dichroic mirror receives 2-4 sets of pump lasers of different wavelengths, combines them, and then transmits them sequentially to the filters and output lenses.

[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 laser wavelength emitted by each group of pump light chips is within the range of 900nm-1000nm.

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

[0014] In one specific embodiment, the mirror bodies of the coupling mirror group and / or the output mirror group each contain a metallized deposition layer, which 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 group and / or output mirror group are welded to the housing by precisely melting metallic copper with a nanosecond large pulse laser.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This invention provides a lightweight, high-power pump source. The encapsulated housing is made of a specific lightweight material, which not only maintains excellent mechanical properties and stability, but also minimizes deformation under environmental temperature changes and external stress, ensuring the precise arrangement and long-term reliability of the internal components. 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 industrial demand for lightweight high-power laser systems. Simultaneously, this invention introduces a multi-wavelength pump source, which not only optimizes the wavelength distribution of the pump light to better match the absorption characteristics of ytterbium-doped fiber, but also effectively disperses the thermal load of the ytterbium-doped fiber, significantly increasing the threshold of mode instability effects, thereby effectively improving the power output capability and long-term operational stability of the fiber laser system. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the structure of a lightweight, high-power pump source according to the present invention.

[0019] Figure 2 is a schematic diagram of the structure of the coupling mirror group or output mirror group after metallization according to the present invention.

[0020] Figure 3 is a schematic diagram of the structure of the coupling mirror group or output mirror group of the present invention after being welded to the housing. Detailed Implementation

[0021] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] As shown in Figure 1, this embodiment provides a lightweight, high-power pump source, including a housing 10 and N groups of pump optical chips 20 partitioned and installed within the housing 10, where N is an integer greater than or equal to 1. Each pump optical chip in each group includes its own corresponding coupling mirror group 30. Each group of pump optical chips is used to emit pump lasers of different wavelengths, which are then shaped by their respective coupling mirror groups 30 and coupled to an output optical fiber (not shown in the figure) via an output mirror group 40. The housing 10 is made of graphene-reinforced aluminum matrix composite material. The housing processed from graphene-reinforced aluminum matrix composite material has characteristics such as low density, high thermal conductivity, and high rigidity, enabling the housing 10 to not only maintain excellent mechanical properties and stability but also withstand changes in ambient temperature and external stresses. Maintaining minimal deformation under force ensures precise arrangement and long-term reliability of internal components of the pump source. More importantly, its density is far lower than that of oxygen-free copper, effectively reducing the weight of the pump source per unit power. This improvement makes the entire fiber laser system lighter, easier to install and maintain, and greatly meets the urgent industrial demand for lightweight high-power laser systems. Furthermore, the lightweight high-power pump source provided in this embodiment introduces a multi-wavelength pump chip, which not only optimizes the wavelength distribution of the pump light to better match the absorption characteristics of ytterbium-doped fiber, but also effectively disperses the thermal load of the ytterbium-doped fiber, significantly increasing the threshold for mode instability effects, thereby improving the power output capability and long-term operational 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 collimating mirror (attached to the laser diode chip), a slow-axis collimating mirror 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 collimating mirror and the slow-axis collimating mirror 301. The fast-axis collimating mirror is used to collimate the pump laser in the direction with a larger divergence angle (usually parallel to the PN junction direction), and the slow-axis collimating mirror 301 is used to collimate the pump laser in the direction with a smaller divergence angle (usually perpendicular to the PN junction direction). The fast-axis collimating mirror and the slow-axis collimating mirror 301 work together to ensure that the pump laser maintains a high collimation characteristic during transmission. The pump laser is then adjusted at its transmission angle by a reflector 302 to ensure accurate transmission to the output mirror group downstream of the optical path. It can be understood that after each laser diode chip emits a pump laser, it is collimated by its corresponding fast-axis collimating lens 301 and then adjusted at its corresponding reflector 302 before finally being transmitted to the output mirror group 40. An adjustment reflector 50 corresponding to each group of laser diode chips is also provided. This adjustment reflector 50 receives pump lasers emitted from the same echelon of M laser diodes arranged in a stepped manner in the same area and adjusts its angle to ensure that each received pump laser beam is effectively transmitted to the output mirror group 40. The focal length of the fast-axis collimating lens and slow-axis collimating lens corresponding to each group of laser diode chips varies depending on the wavelength of the pump laser emitted by the laser diode chip. 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 reflection efficiency.

[0026] In one specific embodiment, the output mirror group 40 includes N-1 dichroic mirrors 401, filters 402, and output lenses 403. Each dichroic mirror 401 receives 2-4 groups of pump lasers of different wavelengths, combines them, and then transmits them sequentially to the filters 402 and the output lenses 403. Each dichroic mirror 401 can reflect a specific wavelength of laser while allowing other wavelengths of laser to pass through, thereby realizing the combination of multi-wavelength pump lasers. The filters 402 can prevent stray light in the fiber laser system from reflecting back to the pump source and damaging the pump chip. Finally, the pump laser is focused by the output lenses 403 and transmitted into the output fiber with high power density and small spot size.

[0027] In one specific embodiment, a heat dissipation layer is coated on the inner surface of the housing 10 to enhance the heat dissipation capacity of the housing 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, which can effectively conduct heat from the pump chip to the housing.

[0028] In one specific embodiment, the pump lasers of different wavelengths emitted by each or every two groups of pump optical chips are all located within the absorption band of the ytterbium-doped gain medium, and can be effectively absorbed by the gain medium, resulting in population inversion. The laser wavelengths emitted by each group of pump optical chips are within the range of 900nm-1000nm. For example, the pump lasers emitted by the first group of pump optical chips 201 and the second group of pump optical chips 202 have a wavelength of 915nm, and the pump lasers emitted by the third group of pump optical chips 203 and the fourth group of pump optical chips 204 have a wavelength of 976nm. It is understood that a fifth and 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 ytterbium-doped fiber, but also effectively disperses the thermal load of ytterbium-doped fiber, significantly increases the threshold of mode instability effects, thereby improving the power output capability and long-term operational stability of the fiber laser system.

[0029] In one specific embodiment, the output mirror group 403 has an achromatic focusing function and can be a cemented doublet lens, an aspherical achromatic lens, a triple achromatic lens, etc. When the pump laser passes through these output mirror groups 403, pump lasers of different wavelengths will be focused onto the same focal point, ensuring that the pump laser is coupled to the output fiber with high energy density and small spot size.

[0030] As shown in Figures 2 and 3, in one specific embodiment, the sides of the mirror bodies of the coupling mirror group 30 and / or the output mirror group 40 are covered with metallized deposition layers to facilitate welding and installation. The metallized deposition layers include an adhesive layer 601, a barrier layer 602, and a welding layer 603 formed using titanium, platinum, or gold. The adhesive layer 601 is used to enhance the adhesion of the deposited metal, ensuring that the deposition 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 enhance the wettability of the deposited metal, enabling the solder 60 to melt at a specific point under the action of the nanosecond high-pulse laser and achieve a high-strength connection with the housing, ensuring a firm connection between the mirror body and the housing, and improving the stability and reliability of the pump source. The solder can be copper, silver, tin, etc.

[0031] It should be noted that, for those skilled in the art, it is obvious 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 characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0032] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A lightweight, high-power pump source, characterized in that: The system includes a housing and N groups of pump optical chips, each group being an integer greater than or equal to 1. Each group of pump optical chips contains its own corresponding coupling mirror group. Each group of pump optical chips emits pump lasers of different wavelengths, which are then shaped by their respective coupling mirror groups and coupled to the output optical fiber via output mirror groups. The coupling mirror groups include a fast-axis collimating mirror, a slow-axis collimating mirror, and a reflecting mirror arranged along the optical path. The fast-axis collimating mirror is used to collimate the pump laser in the direction of a larger divergence angle, and the slow-axis collimating mirror is used to collimate the pump laser in the direction of a smaller divergence angle. The planes containing the larger and smaller divergence angles are rotated 90° about the laser propagation direction. The reflecting mirror 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 also provided. The adjustment reflector is used to receive the pump laser emitted by the M laser diodes in the same echelon and adjust the angle so that each received pump laser beam 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 sequentially to the filters and output lenses. Each dichroic mirror can reflect a specific wavelength of laser while allowing other wavelengths of laser to pass through, thereby realizing the combination of multi-wavelength pump lasers. The filters can prevent stray light in the fiber laser system from reflecting back to the pump source and damaging the pump chip. Finally, the pump laser is focused by the output lens and transmitted into 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 casing is coated 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 laser wavelength emitted by each pump optical chip is within the range of 900nm-1000nm.

5. A 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 cemented doublet, an aspherical achromatic lens, or a triple achromatic lens.

6. The lightweight, high-power pump source according to claim 1, characterized in that: The mirror bodies of the coupling mirror group and / or output mirror group each contain a metallized deposition layer, which includes an adhesive layer, a barrier layer, and a welding layer formed using titanium, platinum, and gold.

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

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