CN103022865A - Multi-wavelength pumping composite fiber optic laser - Google Patents

Abstract

The present invention proposes a multi-wavelength pump synthesis fiber laser, including: a plurality of synthesis modules, used to synthesize a plurality of pump lights of different wavelengths through a plurality of filters of different wavelength bands; a plurality of coupling lenses for The synthesized multi-wavelength pump light is converged and coupled into the input fiber of the pump coupler; and the pump coupler is used to inject multiple multi-wavelength synthesized pump lights into multiple input fibers respectively and synthesize a route output The output of the optical fiber is used as the pumping light of the fiber laser, wherein the image square focus of the coupling lens coincides with the end face center of an input optical fiber of the pumping coupler. According to the multi-wavelength pump synthesis fiber laser of the embodiment of the present invention, the pump light of a certain wavelength is transmitted through the optical filters of multiple synthesis modules, while the pump light of other wavelengths is reflected, and then the pump light is transmitted by the pump coupler. Its multiple pump lights are aggregated to obtain pump light with better beam quality and higher brightness, which improves the power and slope efficiency of the fiber laser.

Description

Multi-Wavelength Pumped Synthetic Fiber Laser

technical field

The invention relates to the field of fiber laser technology, in particular to a multi-wavelength pumped synthetic fiber laser.

Background technique

High-energy and high-power fiber lasers and fiber amplifiers have broad application prospects in industrial processing, medical and health care, and national defense and military affairs due to their advantages such as good beam quality, high efficiency, long life, and compact structure. With the expansion of application fields, higher requirements are placed on the power of fiber lasers.

In order to realize the pumping of fiber lasers, a pump coupler with an all-fiber structure is usually used to synthesize multiple single-band pumps. In this method, optical fiber is used to transmit pumping light, and a pumping coupler made of fused taper is used to synthesize pumping light in the same wavelength band. However, the quality of the pump light beam synthesized by this method is poor, so that the brightness of the pump light becomes low, and because the pump light of a single band is used, the absorption of the pump light by the gain medium is concentrated on one absorption peak, and the absorption The pumping capability is limited, which adversely affects parameters such as output power and efficiency of fiber lasers.

Contents of the invention

The object of the present invention is to solve at least one of the above-mentioned technical drawbacks.

In order to achieve the above object, an embodiment of the present invention proposes a multi-wavelength pump synthesis fiber laser, including: a plurality of synthesis modules, which are used to synthesize a plurality of pump lights of different wavelengths through a plurality of filters of different wavelength bands a plurality of coupling lenses, used to converge and couple the synthesized multi-wavelength pump light into the input fiber of the pump coupler; a pump coupler, used to combine the multi-channel multi-wavelength synthesis pump The pumping light is respectively injected into the plurality of input fibers and then synthesized into a routing output fiber for output as the pumping light of the fiber laser, wherein the image square focal point of the coupling lens and an input fiber of the pumping coupler The center of the end face coincides; the gain fiber is used to absorb the pump light to generate spontaneous emission light; and a pair of fiber gratings is used to form a resonant cavity, wherein the spontaneous emission light of a specific wavelength is reflected multiple times in the resonant cavity and Laser output is amplified by the gain fiber.

According to the multi-wavelength pump synthesis fiber laser of the embodiment of the present invention, the pump light of a certain wavelength is transmitted through the filters of multiple synthesis modules, while the pump light of other wavelengths is reflected, and then the pump light is transmitted by the pump coupler. Its multiple pump lights are aggregated to obtain pump light with better beam quality and higher brightness, which improves the power and slope efficiency of the fiber laser.

In one embodiment of the present invention, the primary filter may be a narrow-band interference filter, a long-wave pass filter, or a short-wave pass filter.

In one embodiment of the present invention, each synthesis module of the plurality of synthesis modules specifically includes: a plurality of semiconductor lasers with different wavelengths, used to generate laser light with a plurality of different wavelengths through the plurality of semiconductor lasers with different wavelengths a plurality of collimating lenses, used to collimate the multiple lasers of different wavelengths into a plurality of parallel light beams; and a synthesis unit, the synthesis unit is composed of a plurality of filters of different wave bands arranged according to certain rules, It is used for transmitting or reflecting the plurality of parallel light beams by a plurality of filters of different wavelength bands through the filter to generate synthetic light.

In one embodiment of the present invention, the optical filter is a narrow-band interference filter, a long-wave pass filter or a short-wave pass filter.

In one embodiment of the present invention, the optical filter is an optical filter resistant to high power and high energy laser.

In one embodiment of the present invention, the optical filter only transmits the corresponding path of pumping light, and reflects all other paths of pumping light.

In one embodiment of the present invention, the optical filter forms a certain angle with the optical path.

In one embodiment of the present invention, the pump coupler has multiple input optical fibers and one output optical fiber.

In one embodiment of the present invention, each input fiber of the pump coupler inputs a bundle of multi-wavelength synthesized pump light, and the output fiber is fusion-connected to the gain fiber.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

1 is a block diagram of a multi-wavelength pumped synthetic fiber laser according to an embodiment of the present invention;

Fig. 2 is a schematic structural view of a multi-wavelength pumped synthetic fiber laser according to an embodiment of the present invention; and

Fig. 3 is a schematic structural diagram of a multi-wavelength pumped synthetic fiber laser according to another embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

In the description of the present invention, it should be understood that the terms "first" and "second" are used for description purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

FIG. 1 is a block diagram of a multi-wavelength pumped synthetic fiber laser according to one embodiment of the present invention. As shown in FIG. 1 , the multi-wavelength pumped synthesis fiber laser according to the embodiment of the present invention includes: multiple synthesis modules 100 , multiple coupling lenses 200 , pump coupler 300 , gain fiber 400 and a pair of fiber gratings 500 .

The multiple synthesizing modules 100 are used for synthesizing multiple lasers of different wavelengths through multiple optical filters of different wavelength bands.

In an embodiment of the present invention, each combining module 100 of the multiple combining modules specifically includes: multiple semiconductor lasers with different wavelengths, multiple collimating lenses, and a combining unit.

Multiple semiconductor lasers with different wavelengths are used to generate multiple lasers with different wavelengths through multiple semiconductor lasers with different wavelengths.

Multiple collimating lenses are used to collimate multiple laser beams with different wavelengths into multiple parallel beams.

The synthesis unit is composed of a plurality of filters of different wavelength bands arranged according to certain rules, and is used to transmit or reflect multiple parallel light beams through the filters to generate synthetic light. Wherein, the filter is a narrow-band interference filter, a long-wave pass filter or a short-wave pass filter.

In one embodiment of the present invention, the optical filter is an optical filter resistant to high power and high energy laser, and forms a certain angle with the optical path.

In one embodiment of the present invention, the optical filter only transmits the corresponding path of pumping light, and reflects all other paths of pumping light, so that multiple wavelengths are synthesized.

In one embodiment of the present invention, the pump coupler has multiple input fibers and one output fiber.

Each input fiber of the pump coupler inputs a bundle of multi-wavelength synthesized pump light, and the output fiber is fusion-connected with the gain fiber.

Multiple coupling lenses 200 are used to converge and couple the combined multi-wavelength pump light into the input fiber of the pump coupler.

The pump coupler 300 is used to inject multiple multi-channel multi-wavelength synthesized pump light into multiple input fibers and then synthesize an output fiber for output as the pump light of the fiber laser, wherein the image square focus of the coupling lens and the pump The centers of the end faces of one input fiber of the coupler coincide.

The gain fiber 400 is used to absorb pump light to generate spontaneous emission light.

A pair of fiber gratings 500 is used to form a resonant cavity, in which spontaneous emission light of a specific wavelength is reflected multiple times in the resonant cavity and amplified by the gain fiber to generate laser output.

Example 1:

Fig. 2 is a schematic structural diagram of a multi-wavelength pumped synthetic fiber laser according to an embodiment of the present invention. As shown in Figure 2, 1-6 are semiconductor lasers with different wavelengths, 7-11 are narrow-band interference filters with 5 different cut-off wavelengths, 12 is a coupling lens, 13 is a pump coupler, and 14 is a pair of fiber gratings , 15 is the gain fiber. Among them, 7-11 and semiconductor lasers with corresponding wavelengths are arranged in a certain order, and the narrow-band interference filter 7-11 forms an angle of 45 degrees with the optical path.

In one embodiment of the present invention, the pump light of 960nm is not in the transmission wavelength range of all filters, and is reflected by each filter. The 965nm pump light is in the transmission center wavelength of the optical filter 7 and not in the transmission wavelength range of other optical filters. After passing through the optical filter 7, it is reflected by the optical filters 8-11. The 970nm pump light is in the transmission center wavelength of filter 8 and is not in the transmission wavelength range of other filters. After passing through 8, it is reflected by filters 9-11. The 975nm pump light is in the transmission center wavelength of filter 9 and not in the transmission wavelength range of other filters. After passing through 9, it is reflected by filters 10 and 11. The 980nm pump light is in the transmission center wavelength of the optical filter 10 and not in the transmission wavelength range of other optical filters. After passing through the optical filter 10, it is reflected by the optical filter 11. Finally, the 6 channels of pump light arrive at the optical filter 11 along the same path and are combined for output. The coupling lens 12 converges each channel of pump light into a bundle of multi-wavelength synthesized pump light, which is coupled into an input optical fiber of the pump coupler 13 middle. The pump coupler 13 couples multiple channels of multi-wavelength synthesized pump light into an output optical fiber as the pump light of the fiber laser.

Example 2:

Fig. 3 is a schematic structural diagram of a multi-wavelength pumped synthetic fiber laser according to another embodiment of the present invention. As shown in Figure 2, 1-6 are semiconductor lasers with different wavelengths, 18-22 are long-pass interference filters with 5 different cut-off wavelengths, 12 is a coupling lens, 13 is a pump coupler, and 14 is a pair of optical fibers Grating, 15 is gain fiber, 16 is semiconductor laser output and 17 is collimating lens. Among them, 18-22 and semiconductor lasers with corresponding wavelengths are arranged in a certain order, and the long-wavelength interference filter 18-22 forms an included angle of 45 degrees with the optical path.

Each path of pump light output by the pigtail 16 is collimated by the collimating lens 17 into a parallel output beam. In one embodiment of the present invention, the 960nm pump light generated by the semiconductor laser 1 is not in the transmission band of all filters, and is reflected by each filter. The 965nm pump light generated by the semiconductor laser 2 is in the transmission wavelength range of the optical filter 18 and not in the transmission wavelength range of the following optical filters. After passing through the optical filter 18, it is reflected by the optical filters 19-22. The 970nm pump light generated by the semiconductor laser 3 is in the transmission wavelength range of the optical filter 19 and not in the transmission wavelength range of the following optical filters. After passing through the optical filter 19, it is reflected by the optical filters 20-22. The 975nm pump light generated by the semiconductor laser 4 is in the transmission wavelength range of the optical filter 20 and not in the transmission wavelength range of the following optical filters. After passing through the optical filter 20, it is reflected by the optical filters 21-22. The 980nm pump light generated by the semiconductor laser 5 is in the transmission wavelength range of the optical filter 21 and not in the transmission wavelength range of the subsequent optical filter. After passing through the 21 , it is reflected by the optical filter 22 . Finally, the 6 channels of pumping light arrive at the filter 22 along the same path and are combined for output. The coupling lens 12 converges the pumping lights of each channel into a beam of multi-wavelength synthetic pumping light, and couples it into an input of the pumping coupler 13. in the fiber. The pump coupler 13 couples multiple channels of multi-wavelength synthesized pump light into an output optical fiber as the pump light of the fiber laser.

It should be noted that this is only an embodiment of a synthesis module. In the present invention, multiple synthesis modules can be combined for multiple pump lights of different wavelengths, and they can be connected to the pump coupler through an optical fiber to achieve more different wavelengths. Synthesis of wavelength pump light.

According to the multi-wavelength pump synthesis fiber laser of the embodiment of the present invention, the pump light of a certain wavelength is transmitted through the filters of multiple synthesis modules, while the pump light of other wavelengths is reflected, and then the pump light is transmitted by the pump coupler. Its multiple pump lights are aggregated to obtain pump light with better beam quality and higher brightness, which improves the power and slope efficiency of the fiber laser.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations to the present invention. Variations, modifications, substitutions, and modifications to the above-described embodiments are possible within the scope of the present invention.

Claims (8)

1. A multi-wavelength pumped synthetic fiber laser, characterized in that, comprising: Multiple synthesizing modules for synthesizing pump lights of multiple different wavelengths through multiple optical filters of different wavelength bands; A plurality of coupling lenses, used to converge and couple the synthesized multi-wavelength pump light into the input fiber of the pump coupler; The pump coupler is used to inject the multi-channel multi-wavelength synthesized pump light into the multiple input fibers respectively and then synthesize an output fiber for output as the pump light of the fiber laser, wherein the coupling lens The focal point of the image square coincides with the end face center of an input optical fiber of the pump coupler; A gain fiber for absorbing the pump light to generate spontaneous emission light; and A pair of fiber gratings is used to form a resonant cavity, wherein spontaneous emission light of a specific wavelength is reflected multiple times in the resonant cavity and amplified by the gain fiber to generate laser output. 2. multi-wavelength pumping synthesis fiber laser as claimed in claim 1, is characterized in that, each synthesis module of described multiple synthesis modules specifically comprises: A plurality of semiconductor lasers of different wavelengths, used to generate pumping light of a plurality of different wavelengths through the plurality of semiconductor lasers of different wavelengths; a plurality of collimating lenses for collimating the plurality of laser light of different wavelengths into a plurality of parallel beams; and A synthesis unit, the synthesis unit is composed of a plurality of filters of different wave bands arranged according to a certain rule, and is used for transmitting or Reflections generate synthetic light. 3. The multi-wavelength pumped synthetic fiber laser according to claim 1 or 2, wherein the filter is a narrow-band interference filter, a long-wave pass filter or a short-wave pass filter. 4. The multi-wavelength pumped synthetic fiber laser according to claim 2, wherein the optical filter is an optical filter resistant to high power and high energy laser. 5. The multi-wavelength pumped synthetic fiber laser as claimed in claim 2 or 3, wherein the optical filter only transmits one path of pumping light corresponding to it, and does not affect the pumping light of other paths. reflection. 6. The multi-wavelength pumped synthetic fiber laser according to claim 1, wherein the optical filter forms a certain angle with the optical path. 7. The multi-wavelength pumped synthetic fiber laser according to claim 1, wherein the pump coupler has multiple input optical fibers and one output optical fiber. 8. multi-wavelength pumping synthetic fiber laser as claimed in claim 2 or 4, is characterized in that, each road input optical fiber of described pumping coupler inputs a bunch of multi-wavelength synthetical pumping light, output optical fiber and gain fiber fusion connect.

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