CN-224233128-U - Inner cavity frequency doubling blue light fiber laser welding device based on fiber bragg grating

CN224233128UCN 224233128 UCN224233128 UCN 224233128UCN-224233128-U

Abstract

The utility model discloses an inner cavity frequency doubling blue light fiber laser welding device based on a fiber grating, and relates to the technical field of fiber lasers. The semiconductor pumping light source is connected to the input end of the optical fiber wavelength division multiplexer, the output end of the semiconductor pumping light source is sequentially connected with ytterbium-doped optical fiber, a frequency doubling crystal and an end surface reflecting mirror, the optical fiber Bragg grating is inscribed by adopting a purple photomask method and is connected to the other input end of the wavelength division multiplexer, then the semiconductor pumping light source is sequentially connected with a dichroic mirror, a collimator and a welding head, ions in the ytterbium-doped optical fiber generate stimulated radiation under the excitation of pumping light, laser oscillates in a resonant cavity formed by the optical fiber Bragg grating and the end surface reflecting mirror, 490nm blue light is generated through the frequency doubling crystal, the dichroic mirror transmits the blue light and reflects 980nm light, and finally the blue light is output through the welding head. The fiber bragg grating has the advantages of high inscription resolution, high stability, high production efficiency, high cavity frequency multiplication electro-optical conversion efficiency, high output blue light beam quality and compact structure, and is suitable for welding high-reflectivity materials.

Inventors

ZHAO JINGPING
HAN ZHI
WANG YIZHANG
ZHONG JIANRONG

Assignees

北京蓝牧激光科技有限公司

Dates

Publication Date: 20260512
Application Date: 20250718

Claims (6)

1. An inner cavity frequency doubling blue light fiber laser welding device based on fiber bragg gratings is characterized by comprising a fiber wavelength division multiplexer (102); The input end of the optical fiber wavelength division multiplexer (102) is connected with one end of the optical fiber Bragg grating (106), and the other end of the optical fiber Bragg grating (106) is sequentially connected with a dichroic mirror (107), a collimator (108) and a welding head (109); The output end of the optical fiber wavelength division multiplexer (102) is sequentially connected with an ytterbium-doped optical fiber (103), a frequency doubling crystal (104) and an end surface reflecting mirror (105); the input end of the optical fiber wavelength division multiplexer (102) is also connected with a semiconductor pumping source (101).
2. The fiber bragg grating-based intracavity frequency doubling blue-ray fiber laser welding device according to claim 1, wherein the fiber bragg grating (106) and the end surface reflecting mirror (105) are respectively used as a front cavity mirror and a rear cavity mirror to form a resonant cavity.
3. The fiber grating-based intracavity frequency-doubled blue-ray fiber laser welding device of claim 1 wherein the semiconductor pump source (101) is a 915nm semiconductor pump source.
4. The fiber grating-based intracavity frequency-doubled blue-light fiber laser welding device of claim 1 wherein the fiber wavelength division multiplexer (102) is a 915/978nm fiber wavelength division multiplexer.
5. The fiber bragg grating-based inner cavity frequency doubling blue-ray fiber laser welding device according to claim 1, wherein the fiber bragg grating (106) is a fiber bragg grating with a reflection spectrum center wavelength of 980nm obtained by a purple photomask engraving method.
6. The fiber grating-based intracavity frequency-doubled blue fiber laser welding device of claim 1 wherein the dichroic mirror (107) has a blue light transmittance of greater than 90% for 490nm and a light reflectance of greater than 90% for 980 nm.

Description

Inner cavity frequency doubling blue light fiber laser welding device based on fiber bragg grating Technical Field The utility model relates to the technical field of fiber lasers, in particular to an inner cavity frequency doubling blue-ray fiber laser welding device based on a fiber grating. Background In the welding field, infrared fiber lasers of the kilowatt class are widely used, and are favored for their high efficiency and high power. However, the infrared band laser does not perform well in the face of high-reflectivity metals such as Al, cu, au, and the like. The high-reflectivity metal has lower absorptivity to infrared laser, about 5 percent of the high-reflectivity metal has low energy conversion efficiency, and the defects of air holes, cracks, unfused and the like are easy to occur in the processing process, and the absorptivity of the blue light wave band laser with the wavelength of 450-500nm is improved by more than 10 times, so that the blue light laser has great potential in the welding field of high-reflectivity nonferrous metal materials. Although blue lasers have great application prospects, there are some bottlenecks in the technical development. In the prior art, blue light is obtained from a solid laser, a semiconductor material is generally used for directly manufacturing a semiconductor laser diode in a blue light wave band, expensive equipment and substrate materials are required for developing the blue light diode by the method, the output light beam quality is poor, and the method is greatly limited in the welding field. The method for outputting the blue laser through frequency multiplication of the fiber laser is mainly realized through external cavity frequency multiplication of a space structure, and in the external cavity frequency multiplication, a laser beam only passes once when passing through a frequency multiplication crystal, so that the light intensity of the laser beam is obviously reduced, and the frequency conversion efficiency is lower. And to achieve a considerable frequency doubling output, external cavity frequency doubling typically requires higher pump power, which results in higher system energy consumption and cost. Therefore, how to provide an inner cavity frequency multiplication blue light fiber laser welding device based on fiber bragg gratings, which can reduce the energy consumption and complexity of the system and realize the blue light output with high power and high beam quality is a problem to be solved by the technicians in the field. Disclosure of utility model In view of the above, the utility model provides an inner cavity frequency doubling blue-ray fiber laser welding device based on fiber gratings, wherein the fiber gratings are manufactured by adopting a method of writing by a purple photomask, and the fiber gratings written by the method have high resolution, higher stability and high production efficiency, and are suitable for harsh industrial environments. Meanwhile, the electro-optic conversion efficiency is high by adopting the method of inner cavity frequency multiplication, the obtained blue laser output has higher beam quality, and the method is suitable for welding high-reflectivity materials. In order to achieve the above purpose, the present utility model adopts the following technical scheme: An inner cavity frequency doubling blue light fiber laser welding device based on fiber bragg grating comprises a fiber wavelength division multiplexer; The input end of the optical fiber wavelength division multiplexer is connected with one end of the optical fiber Bragg grating, and the other end of the optical fiber Bragg grating is sequentially connected with a dichroic mirror, a collimator and a welding head; The output end of the optical fiber wavelength division multiplexer is sequentially connected with an ytterbium-doped optical fiber, a frequency doubling crystal and an end surface reflecting mirror; The input end of the optical fiber wavelength division multiplexer is also connected with a semiconductor pumping source. Preferably, the fiber Bragg grating and the end surface reflector are respectively used as a front cavity mirror and a rear cavity mirror to form a resonant cavity. Preferably, the semiconductor pump source is 915nm semiconductor pump source. Preferably, the optical fiber wavelength division multiplexer is 915/978nm optical fiber wavelength division multiplexer. Preferably, the fiber Bragg grating is a fiber Bragg grating with the central wavelength of a reflection spectrum of 980nm obtained by adopting a purple photomask engraving method. Preferably, the dichroic mirror has a blue light transmittance of greater than 90% for 490nm and a light reflectance of greater than 90% for 980 nm. Compared with the prior art, the utility model discloses an inner cavity frequency doubling blue-ray fiber laser welding device based on the fiber grating, which is characterized in that a purple photomask method is adopted to w