CN111694162A - Spectrum synthesis method and device - Google Patents

Abstract

The invention discloses a spectrum synthesis method and device, aiming at solving the technical problem in the prior art that the number of synthesis paths of the spectrum synthesis method is only tens of paths, and the beam quality of the final spectrum synthesis cannot be guaranteed. The invention adopts the tunable technology to divide the wide-spectrum super-fluorescence light source, realizes the division of hundreds of seed lasers, realizes the output of the fiber laser with a narrow linewidth of thousands of kilowatts through the adjustable filter power amplifying component, and then realizes the spectrum through the diffraction grating and the dense fiber array. Synthesize and divide a part of the light as the reference light, and perform spectral transformation through the front-end tunable technology to realize the establishment of final feedback control and ensure the final beam quality. The spectral synthesis method and device of the present invention can realize spectral synthesis of dozens or even hundreds of channels in a limited space, and by establishing a real-time feedback control system, the degradation of beam quality caused by external factors such as temperature, humidity, and jitter can be overcome, and the spectrum can be guaranteed. Synthetic effect.

Description

A kind of spectral synthesis method and device

technical field

The invention relates to spectral synthesis of high-power and high-beam quality fiber laser output, in particular to a spectral synthesis method and device.

Background technique

Spectral synthesis technology uses dispersive optical elements to synthesize fiber lasers of different wavelengths into a single beam of laser output. Because of its simple structure, strong expansibility, good quality of the synthesized beam, and no complex regulation, it is currently the only way to achieve high brightness and high power fiber. Efficient technical approach to laser systems.

In the prior art, in order to ensure the beam quality of the spectral beam, the linewidth of each laser must be less than 35 GHz. However, due to the influence of problems such as stimulated Brillouin scattering, self-phase modulation, mode instability, etc. It is difficult to increase the output power of fiber lasers, and due to thermal distortion, ambient temperature changes, jitter and other reasons, the quality of the system's spectrally synthesized beam will be degraded, which will affect the application effect. In dozens of channels, and the beam quality of the final spectral synthesis cannot be guaranteed.

SUMMARY OF THE INVENTION

The present invention aims to solve the technical problem in the prior art that the spectral synthesis method has only tens of channels and cannot guarantee the beam quality of the final spectral synthesis, and provides a spectral synthesis method and device.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A spectral synthesis method, which is special in that it includes the following steps:

Step 1) splitting the initial light source into multiple seed wide-spectrum light sources;

Step 2) wavelength tuning is performed on each seed wide spectral light source to form a narrow linewidth light source;

Step 3) amplifying the power of each narrow linewidth light source;

Step 4) densely arranging the multiple narrow linewidth light sources after power amplification to form an optical fiber array;

Step 5) collimating and focusing the light beams of each path in the fiber array as a whole, so that all the light beams are focused on one focal point;

Step 6) performing optical path synthesis at the focal point to form a spectrally synthesized beam;

Step 7) splitting the spectrally synthesized beam to form reflected light and transmitted light;

The reflected light is input to the power meter or the target surface;

The transmitted light is imaged after being focused, and the tuning wavelength in step 2) is controlled according to the imaging effect, so as to control the beam quality of the reflected light output.

Further, the initial light source in step 1) is a broad-spectrum hyperfluorescence light source.

Further, the reflected light in step 7) accounts for more than 99% of the combined light path.

Further, in step 3), each narrow linewidth light source is sequentially amplified by the pumping combiner and the gain fiber of the amplifier stage.

Further, in step 7), the transmitted light is focused by a focusing lens and then incident on the CCD for imaging.

Based on the above-mentioned spectrum synthesis method, the present invention also provides a spectrum synthesis device, which is special in that it includes a laser light source, a beam splitter, an adjustable filter power amplifying component, a zoom mirror, and a diffraction grating arranged in sequence. , beam splitter, and focusing lens and CCD;

The laser light source emits a broad-spectrum initial light source;

The beam splitter divides the initial light source into multiple seed wide-spectrum light sources;

Each channel of the seed wide-spectrum light source is provided with an adjustable filter power amplifying component;

The tunable filter power amplifying component includes a tunable filter, a pump combiner, and a gain fiber;

The optical signal input end of the tunable filter is used for receiving a seed wide-spectrum light source;

The optical signal input end of the pump beam combiner is connected with the optical signal output end of the tunable filter, the pump end is connected with the pump source, and the optical signal output end is connected with the input end of the gain fiber;

The output end of the gain fiber is connected to the transmission fiber;

All transmission fibers are closely arranged to form a fiber array;

The output light of the optical fiber array is focused at the same focus by the zoom mirror;

the diffraction grating is located at the focal point for forming a spectrally combined beam;

The beam splitter divides the spectrally combined beam into reflected light and transmitted light;

The reflected light is incident on the power meter or the target surface;

The transmitted light is incident on the CCD after being focused by the focusing lens;

The CCD is located at the focal point of the focusing lens, and is connected to the electrical signal feedback end of the tunable filter for imaging the focused beam and feeding back the imaging information to the tunable filter.

Further, the reflectivity of the beam splitter is 99.9%.

Further, a reflector is also included; the reflector is located between the beam splitter and the focusing lens, and is used for reflecting the transmitted light to the focusing lens.

Further, the diffraction grating is a prism, a transmission grating or a reflection grating.

Further, the laser light source is a broad-spectrum super-fluorescence light source.

The beneficial effects of the present invention are:

1. The spectral synthesis method and device of the present invention can realize the spectral synthesis of dozens of channels or even hundreds of channels in a limited space, and by establishing a real-time feedback control system, the beam quality degradation caused by external factors such as temperature, humidity, and jitter can be overcome, Guarantee the effect of spectral synthesis.

2. In the present invention, a reflecting mirror is further arranged between the beam splitter and the focusing lens, so that the space setting of each optical device is more reasonable and the occupied space can be reduced.

Description of drawings

FIG. 1 is a schematic structural diagram of a spectral synthesis device of the present invention.

Description of drawings:

1-laser source, 2-beamsplitter, 3-tunable filter, 4-pump combiner, 5-gain fiber, 6-fiber array, 7-zoom mirror, 8-diffraction grating, 9-spectrum Combined beam, 10-beam splitter, 11-power meter, 12-transmitted light, 13-reflector, 14-focusing lens, 15-CCD, 17-pump source.

Detailed ways

In order to make the objectives, advantages and features of the present invention clearer, a spectral synthesis method and apparatus proposed by the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following detailed description. It should be noted that: the accompanying drawings are all in a very simplified form and use inaccurate scales, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention; secondly, the structures shown in the accompanying drawings are often actual structures. part.

The working principle of the present invention is as follows: adopting tunable technology to divide the wide-spectrum super-fluorescence light source, realizing the division of hundreds of seed lasers, and realizing the output of the fiber laser with a narrow linewidth of thousands of kilowatts through the adjustable filter power amplifying component, and then passing through the diffraction grating and dense The optical fiber array realizes spectral synthesis, and divides a part of the light as the reference light, performs spectral transformation through the front-end tunable technology, realizes the establishment of final feedback control, and ensures the final beam quality.

A spectral synthesis device, as shown in FIG. 1 , includes a laser light source 1, a beam splitter 2, an adjustable filter power amplifier assembly, a zoom mirror 7, a diffraction grating 8, a beam splitter 10, and a mirror 13 arranged in sequence , focusing lens 14 and CCD 15;

The laser light source 1 is a broad-spectrum super-fluorescence light source, and the broad-spectrum super-fluorescence light source emits a broad-spectrum initial light source; the beam splitter 2 divides the initial light source into multiple seed broad-spectrum light sources; The tunable filter power amplifier assembly; the tunable filter power amplifier assembly includes a tunable filter 3, a pump beam combiner 4, and a gain fiber 5; the optical signal input end of the tunable filter 3 is used to receive a seed wide-spectrum light source; the pump The optical signal input end of the beam combiner 4 is connected with the optical signal output end of the tunable filter 3, its pump end is connected with the pump source 17, and its optical signal output end is connected with the input end of the gain fiber 5; The output end is connected to the transmission fiber.

All the transmission fibers are tightly arranged and clamped by the fiber array clamp to form the fiber array 6 as a whole; the output light of the fiber array 6 is focused at the same focal point by the zoom mirror 7; The grating 8 is a prism or a transmission grating or a reflection grating. The beam splitter 10 divides the spectrally combined beam 9 into reflected light and transmitted light 12; the reflectivity of the beam splitter 10 is 99.9%; the split reflected light is incident on the power meter 11 or the target surface; the transmitted light 12 first After being reflected by the reflecting mirror 13, it reaches the focusing lens 14, and is incident on the CCD 15 after being focused by the focusing lens 14; The resulting beam is imaged, and the imaging information is fed back to the tunable filter 3 .

The working process of the spectral synthesis device is as follows:

Step 1) The outgoing light of the wide-spectrum super-fluorescent light source is passed through the beam splitter 2 to realize dozens or hundreds of seed wide-spectrum light sources;

Step 2) A tunable filter 3 is set on each channel of seed wide spectral light source, and the tunable filter 3 performs wavelength tuning on the single channel seed wide spectral light source to form a narrow linewidth light source; this tunable filter 3 can also be composed of space Instead of tuning device, it is mainly used to realize low-power single-channel different spectral output, and at the same time, it can adjust the spectrum of each channel to realize subsequent feedback control;

Step 3) The single-channel different spectral output light realizes the power amplification of the single-channel narrow linewidth light source through the pump beam combiner 4 and the gain fiber 5, and the amplified power can reach several kilowatts;

Step 4) All amplified different spectra are densely arranged to form an optical fiber array 6 and output;

Step 5) The laser beams output by each channel are collimated and focused on the beams of each channel through the zoom mirror 7, so that all beams are focused in one focus;

Step 6) Place the diffraction grating 8 at the focal point. The diffraction grating 8 is a prism, a transmission grating or a reflection grating, etc. According to the diffraction angle of the grating, the positional relationship between the light beam and the grating is adjusted, so that the multi-channel spectral laser can pass through the diffraction grating 8. form the best spectrally synthesized beam 9;

Step 7) The spectrally synthesized beam 9 passes through a beam splitter 10 with a reflectivity of 99.9%, most of the reflected light irradiates the power meter 11 or the target surface, and a small part of the transmitted light 12 is focused by the focusing lens 14 through the reflector 13, and the CCD 15 is placed at the focal point of the focusing lens 14, and the spectral synthesis beam effect is displayed on the CCD 15; To achieve the best spectral synthesis effect.

Claims (10)

1. a spectral synthesis method, is characterized in that, comprises the following steps: Step 1) splitting the initial light source into multiple seed wide-spectrum light sources; Step 2) wavelength tuning is performed on each seed wide spectral light source to form a narrow linewidth light source; Step 3) amplifying the power of each narrow linewidth light source; Step 4) densely arranging the multiple narrow linewidth light sources after power amplification to form an optical fiber array; Step 5) collimating and focusing the light beams of each path in the fiber array as a whole, so that all the light beams are focused on one focal point; Step 6) performing optical path synthesis at the focal point to form a spectrally synthesized beam; Step 7) splitting the spectrally synthesized beam to form reflected light and transmitted light; The reflected light is input to the power meter or the target surface; The transmitted light is imaged after being focused, and the tuning wavelength in step 2) is controlled according to the imaging effect, so as to control the beam quality of the reflected light output. 2. a kind of spectral synthesis method according to claim 1, is characterized in that: The initial light source in step 1) is a broad-spectrum hyperfluorescence light source. 3. a kind of spectral synthesis method according to claim 1 and 2, is characterized in that: The reflected light in step 7) accounts for more than 99% of the combined light path. 4. a kind of spectral synthesis method according to claim 3, is characterized in that: The power of each narrow linewidth light source in step 3) is sequentially amplified by the pump combiner and the gain fiber of the amplifier stage. 5. a kind of spectral synthesis method according to claim 4, is characterized in that: The transmitted light in step 7) is focused by the focusing lens and then incident on the CCD for imaging. 6. A spectral synthesizing device based on any of the described spectral synthesizing methods of claims 1 to 5, characterized in that: comprising a laser light source (1), a beam splitter (2), an adjustable filter power amplifying assembly, a zoom mirror (7), a diffraction grating (8), a beam splitter (10), and a focusing lens (14) and a CCD (15); The laser light source (1) emits a broad-spectrum initial light source; The beam splitter (2) divides the initial light source into multiple seed-broad spectrum light sources; Each channel of the seed wide-spectrum light source is provided with an adjustable filter power amplifying component; The tunable filtering power amplifying assembly includes a tunable filter (3), a pumping combiner (4), and a gain fiber (5); The optical signal input end of the tunable filter (3) is used for receiving a seed wide-spectrum light source; The optical signal input end of the pump beam combiner (4) is connected to the optical signal output end of the tunable filter (3), the pump end is connected to the pump source (17), and the optical signal output end is connected to the gain fiber (5) input terminal connection; The output end of the gain fiber (5) is connected to the transmission fiber; All transmission fibers are closely arranged to form a fiber array (6); The output light of the optical fiber array (6) is focused at the same focus by the zoom mirror (7); the diffraction grating (8) is located at the focal point for forming a spectrally combined beam (9); The beam splitter (10) divides the spectrally combined beam (9) into reflected light and transmitted light (12); The reflected light is incident on the power meter (11) or the target surface; The transmitted light (12) is incident on the CCD (15) after being focused by the focusing lens (14); The CCD (15) is located at the focal point of the focusing lens (14), and is connected to the electrical signal feedback end of the tunable filter (3) for imaging the focused beam and feeding back the imaging information to the Tunable filter (3). 7. a kind of spectral synthesis device according to claim 6, its special feature is: The reflectivity of the beam splitter (10) is 99.9%. 8. a kind of spectral synthesis device according to claim 6 or 7, its special feature is: It also includes a reflector (13); the reflector (13) is located between the beam splitter (10) and the focusing lens (14) for reflecting the transmitted light (12) to the focusing lens (14). 9. a kind of spectral synthesis device according to claim 8, its special feature is: The diffraction grating (8) is a prism or a transmission grating or a reflection grating. 10. a kind of spectral synthesis device according to claim 9, its special feature is: The laser light source (1) is a broad-spectrum super-fluorescence light source.

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