阅读说明：本技术 一种二维光谱合成装置 (Two-dimensional spectrum synthesizer ) 是由 沈本剑 李敏 陶汝茂 冯曦 李浩坤 刘玙 王建军 于 2021-11-15 设计创作，主要内容包括：本发明属于激光器领域,本发明公开了一种二维光谱合成装置,该装置包括：沿光路传播方向依次设置的二维光纤光源阵列、高线密度多层介质膜光栅Ⅰ、高线密度多层介质膜光栅Ⅱ、低线密度多层介质膜光栅Ⅰ和低线密度多层介质膜光栅Ⅱ。本发明提供的二维光谱合成装置能够减小多路子光源光谱合成时对大口径、长宽比例大的光学元件的需求,减小合成装置的体积,降低合成装置的成本,实现更高功率的光谱合成输出,为光谱合成装置的广泛应用提供了可能。(The invention belongs to the field of lasers, and discloses a two-dimensional spectrum synthesis device, which comprises: the two-dimensional fiber light source array, the high-linear-density multilayer dielectric film grating I, the high-linear-density multilayer dielectric film grating II, the low-linear-density multilayer dielectric film grating I and the low-linear-density multilayer dielectric film grating II are sequentially arranged along the propagation direction of a light path. The two-dimensional spectrum synthesis device provided by the invention can reduce the requirements on optical elements with large aperture and large length-width ratio during the spectrum synthesis of the multi-path sub-light source, reduce the volume of the synthesis device, reduce the cost of the synthesis device, realize the spectrum synthesis output with higher power, and provide possibility for the wide application of the spectrum synthesis device.)

1. A two-dimensional spectral synthesis apparatus, the apparatus comprising: the two-dimensional fiber light source array (1), the high-linear-density multilayer dielectric film grating I (2), the high-linear-density multilayer dielectric film grating II (3), the low-linear-density multilayer dielectric film grating I (4) and the low-linear-density multilayer dielectric film grating II (5) are sequentially arranged along the propagation direction of a light path;

the two-dimensional optical fiber light source array (1) is composed of a plurality of optical fiber light sources with different wavelengths, two-dimensional array sub-beams emitted by the two-dimensional optical fiber light source array (1) are linearly polarized light beams pointing to be parallel, and the linearly polarized light beams are incident on the high linear density multilayer dielectric film grating I (2) at the same angle; the high-linear-density multilayer dielectric film grating I (2) and the high-linear-density multilayer dielectric film grating II (3) are parallel to each other, and the low-linear-density multilayer dielectric film grating I (4) and the low-linear-density multilayer dielectric film grating II (5) are parallel to each other; the included angle between the grid line direction of the low linear density multilayer dielectric film grating I (4) and the grid line direction of the high linear density multilayer dielectric film grating II (3) is；

The central wavelength interval between adjacent sub-beams emitted by each row of optical fiber light sources in the two-dimensional optical fiber light source array (1) is larger than the central wavelength interval between adjacent sub-beams emitted by each column of optical fiber light sources; or the central wavelength interval between adjacent sub-beams emitted by each row of optical fiber light sources in the two-dimensional optical fiber light source array (1) is smaller than the central wavelength interval between adjacent sub-beams emitted by each column of optical fiber light sources;

the linear density of the high linear density multilayer dielectric film grating I (2) and the high linear density multilayer dielectric film grating II (3) is more than 1500 gr/mm;

the linear density of the low-linear-density multilayer dielectric film grating I (4) and the low-linear-density multilayer dielectric film grating II (5) is less than 1500 gr/mm.

2. The two-dimensional spectrum synthesis device according to claim 1, wherein the incident angle of the two-dimensional array sub-beams emitted by the two-dimensional fiber light source array (1) incident on the high linear density multilayer dielectric film grating i (2) is littrow angle of the wavelength corresponding to the high linear density multilayer dielectric film grating i (2).

3. The two-dimensional spectrum synthesis device according to claim 1, wherein the polarization directions of the two-dimensional array of sub-beams emitted by the two-dimensional fiber light source array (1) are the same and are all perpendicular to the grid line direction of the high-linear-density multi-layer dielectric film grating I (2).

4. A two-dimensional spectrum synthesis device according to claim 1, wherein the high linear density multi-layer dielectric film grating I (2) and the high linear density multi-layer dielectric film grating II (3) are polarization dependent gratings.

5. A two-dimensional spectrum synthesis apparatus according to claim 1, wherein the low-line-density multi-layer dielectric film grating i (4) and the low-line-density multi-layer dielectric film grating ii (5) are polarization-independent gratings.

Technical Field

The invention belongs to the field of lasers, and particularly relates to a two-dimensional spectrum synthesis device.

Background

The laser light source with high beam quality and high average power has important application prospect in the fields of industrial production, equipment manufacturing and the like. When the laser light source is used in the laser cutting field, the laser light source with higher average power and better beam quality means faster cutting rate and thicker cutting capability, but is limited by the nonlinear effect and the influence of mode instability, the output power of the single-fiber single-mode laser has an upper limit, in order to realize the output of the light source with higher power, the output of a plurality of fiber lasers is usually coupled by using a beam combiner, but the coupling mode causes the quality of the combined laser beam to be poor (M is the coupling mode)²Not less than 15) and limits the use of high power lasers.

The spectrum synthesis technology is another technology for realizing high-power and high-beam-quality laser output, and can synthesize a plurality of laser beams with different wavelengths into one laser beam, so that the output total power level is improved, and meanwhile, the better beam quality can be kept. The light sources of the existing spectrum synthesis device are all one-dimensional light source arrays, but are limited by the limitations of the processing capability and the size of optical elements (such as the aperture of a beam expanding system, the aperture of a multilayer dielectric film grating, and the like), and when the spectrum synthesis is performed by adopting the one-dimensional light source, the number of sub-beams of the light source to be synthesized is limited, which means that the spectrum synthesis device adopting the one-dimensional light source cannot realize the expansion of spectrum synthesis of more laser beams, and also means that the improvement of the output laser power of the spectrum synthesis device adopting the one-dimensional light source also has an upper limit. In addition, when the one-dimensional light source is adopted for beam combination, due to the low utilization rate of the optical element and the special structure, the processing difficulty of the optical element is increased, and the whole combining device is large in size, heavy in weight and high in cost along with the increase of the number of light source sub-beams, so that the application of the spectrum combining device is severely limited.

Therefore, in order to effectively expand the light source sub-beams to be synthesized for the spectrum beam combining system, reduce the volume and the mass of the synthesizing device during the synthesis of the multiple laser sub-beams and promote the application of the spectrum synthesizing device, the invention provides the two-dimensional spectrum synthesizing device.

Disclosure of Invention

In view of this, the present invention provides a two-dimensional spectrum synthesis apparatus, which can realize spectrum synthesis of more laser beams, and compared with the one-dimensional spectrum synthesis apparatus in the prior art, the apparatus has small volume and low cost, and provides possibility for wide application of the spectrum synthesis apparatus.

In order to achieve the purpose, the invention adopts the following technical scheme: a two-dimensional spectral synthesis apparatus, the apparatus comprising: the two-dimensional fiber light source array, the high-linear-density multilayer dielectric film grating I, the high-linear-density multilayer dielectric film grating II, the low-linear-density multilayer dielectric film grating I and the low-linear-density multilayer dielectric film grating II are sequentially arranged along the propagation direction of a light path; the two-dimensional fiber light source array is composed of a plurality of fiber light sources with different wavelengths, two-dimensional array sub-beams emitted by the two-dimensional fiber light source array are linearly polarized light beams pointing to be parallel, and the linearly polarized light beams are incident on the high-linear-density multilayer dielectric film grating I at the same angle; the high-linear-density multilayer dielectric film grating I and the high-linear-density multilayer dielectric film grating II are parallel to each other, and the low-linear-density multilayer dielectric film grating I and the low-linear-density multilayer dielectric film grating II are parallel to each other; the included angle between the grid line direction of the low linear density multilayer dielectric film grating I and the grid line direction of the high linear density multilayer dielectric film grating II is；

The central wavelength interval between adjacent sub-beams emitted by each row of optical fiber light sources in the two-dimensional optical fiber light source array is larger than the central wavelength interval between adjacent sub-beams emitted by each column of optical fiber light sources; or the central wavelength interval between adjacent sub-beams emitted by each row of optical fiber light sources in the two-dimensional optical fiber light source array (1) is smaller than the central wavelength interval between adjacent sub-beams emitted by each column of optical fiber light sources;

the linear density of the high linear density multilayer dielectric film grating I and the high linear density multilayer dielectric film grating II is more than 1500 gr/mm; the linear density of the low-linear-density multilayer dielectric film grating I and the low-linear-density multilayer dielectric film grating II is less than 1500 gr/mm.

Preferably, the incident angle of the two-dimensional array sub-beams emitted by the two-dimensional fiber light source array incident to the high-linear-density multilayer dielectric film grating i is a littrow angle of the wavelength corresponding to the high-linear-density multilayer dielectric film grating i.

Preferably, the polarization directions of the two-dimensional array sub-beams emitted by the two-dimensional optical fiber light source array are the same and are all perpendicular to the grid line direction of the high-linear-density multilayer dielectric film grating I.

Preferably, the high linear density multilayer dielectric film grating I and the high linear density multilayer dielectric film grating II are both polarization-dependent gratings or polarization-independent gratings.

Preferably, the low-linear-density multilayer dielectric film grating I and the low-linear-density multilayer dielectric film grating II are polarization-independent gratings.

The invention has the beneficial effects that: the two-dimensional spectrum synthesis device provided by the invention realizes the spectrum synthesis of two-dimensional array sub-beams emitted by the two-dimensional fiber light source by setting the appropriate wavelength interval of the two-dimensional fiber light source array and the linear density of the diffraction grating, compared with a one-dimensional spectrum synthesis device, the two-dimensional spectrum synthesis device synthesizes the same number of laser sub-beams, the size of a required optical element is greatly reduced, the volume of the device is effectively reduced, the cost of the device is reduced, and the possibility is provided for realizing the spectrum synthesis output with higher power; meanwhile, the invention uses the matching of the grating density and the central wavelength interval between the sub-beams to reduce the dispersion of the synthesized beam to the minimum and ensure the quality of the synthesized beam.

Therefore, the two-dimensional spectrum synthesis device provided by the invention can reduce the requirement on a large-aperture optical element during the spectrum synthesis of the multi-path sub-light source, reduce the volume of the synthesis device, reduce the cost of the synthesis device, realize the spectrum synthesis output with higher power and provide possibility for the wide application of the spectrum synthesis device.

Drawings

FIG. 1 is a schematic structural diagram of a two-dimensional spectrum synthesis apparatus according to the present invention;

in the figure: 1. the two-dimensional optical fiber light source array comprises a two-dimensional optical fiber light source array 2, a high-linear-density multilayer dielectric film grating I3, a high-linear-density multilayer dielectric film grating II 4, a low-linear-density multilayer dielectric film grating I5 and a low-linear-density multilayer dielectric film grating II.

Detailed Description

It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.

The invention is described in detail below with reference to the figures and specific embodiments.

A two-dimensional spectral synthesis apparatus as shown in fig. 1, the apparatus comprising: the two-dimensional fiber light source array comprises a two-dimensional fiber light source array 1, a high-linear-density multilayer dielectric film grating I2, a high-linear-density multilayer dielectric film grating II3, a low-linear-density multilayer dielectric film grating I4 and a low-linear-density multilayer dielectric film grating II 5 which are sequentially arranged along the propagation direction of a light path.

The two-dimensional fiber light source array 1 comprises a plurality of fiber light sources with different wavelengths, and can emit two-dimensional array linear polarization beams pointing to be parallel, the two-dimensional array linear polarization beams emitted by the two-dimensional array linear polarization beams are incident to the high-linear-density multilayer dielectric film grating I2 at the same angle, and the incident angle is the Littrow angle of the high-linear-density multilayer dielectric film grating I2 corresponding to the wavelength.

The two-dimensional fiber light source array 1 may be composed of a fiber laser, a solid laser, or a combination thereof and a coherent synthetic light source thereof. In the light path, a high linear density multilayer dielectric film grating I2 and a high linear density multilayer dielectric film grating II3 are parallel to each other, a low linear density multilayer dielectric film grating I4 and a low linear density multilayer dielectric film grating II 5 are parallel to each other, and the included angle between the grid line direction of the low linear density multilayer dielectric film grating I4 and the grid line direction of the high linear density multilayer dielectric film grating II3 is；

The linear density of the high linear density multilayer dielectric film grating I2 and the high linear density multilayer dielectric film grating II3 is more than 1500 gr/mm; the linear density of the low-linear density multilayer dielectric film grating I4 and the low-linear density multilayer dielectric film grating II 5 is less than 1500 gr/mm.

The central wavelength interval range between adjacent sub-beams emitted by each row of the optical fiber light sources of the two-dimensional optical fiber light source array 1 is not overlapped with the central wavelength interval range between adjacent sub-beams emitted by each column of the optical fiber light sources, and the central wavelength interval between adjacent sub-beams emitted by each row of the optical fiber light sources is larger than the central wavelength interval between adjacent sub-beams emitted by each column of the optical fiber light sources; or the central wavelength interval between the adjacent sub-beams emitted by each row of optical fiber light sources is smaller than the central wavelength interval between the adjacent sub-beams emitted by each column of optical fiber light sources; the purpose of designing the center wavelength interval between the sub-beams in the two-dimensional array rows and columns is to match the center wavelength interval of the light source with the high linear density multi-layer dielectric film grating and the low linear density multi-layer dielectric film grating. After two-dimensional array linear polarization light beams emitted by the two-dimensional optical fiber light source array 1 are incident to the high-linear-density multilayer dielectric film grating I2 for diffraction, sub-light beams with smaller central wavelength interval are converged into a light spot on the high-linear-density multilayer dielectric film grating II3 in a row or row mode, and are diffracted by the high-linear-density multilayer dielectric film grating II3 to be combined into a light beam; the distance in the horizontal or vertical direction of each light beam in a row or a column with larger central wavelength interval among all sub-light beams is kept unchanged after passing through a high-linear-density multilayer dielectric film grating I2 and a high-linear-density multilayer dielectric film grating II3, then a light spot is formed on a low-linear-density multilayer dielectric film grating II 5 after being diffracted by a low-linear-density multilayer dielectric film grating I4, the light beam is synthesized after being diffracted by the low-linear-density multilayer dielectric film grating II 5, the high-linear-density multilayer dielectric film grating I2 and the high-linear-density multilayer dielectric film grating II3 synthesize one-dimensional sub-light beams with smaller central wavelength interval, the low-linear-density multilayer dielectric film grating I4 and the low-linear-density multilayer dielectric film grating II 5 synthesize the other one-dimensional sub-light beams with larger central wavelength interval, and simultaneously ensure the lower dispersion of the synthesized one-dimensional light beams.

In the embodiment, the central wavelength interval between each sub-beam in each row in the two-dimensional optical fiber light source array 1 is set to be 0.1 nm-2 nm, the central wavelength interval between each sub-beam in each row is set to be 2.5 nm-60 nm, after a two-dimensional array linear polarized light beam emitted by the two-dimensional optical fiber light source array 1 is incident to the high-linear-density multilayer dielectric film grating I2 for diffraction, because the central wavelength interval of the sub-beam row is small, the sub-beams in each row are converged into a light spot on the high-linear-density multilayer dielectric film grating II3 and are diffracted by the high-linear-density multilayer dielectric film grating II3 to be synthesized into a light beam, and the distance in the vertical direction of each row of sub-beams is kept unchanged through the high-linear-density multilayer dielectric film grating I2 and the high-linear-density multilayer dielectric film grating II 3; and then, a light spot is formed on the low-linear-density multilayer dielectric film grating II 5 after the diffraction of the low-linear-density multilayer dielectric film grating I4, and a beam is synthesized after the diffraction of the low-linear-density multilayer dielectric film grating II 5, so that the two-dimensional spectrum synthesis of the multipath sub-beams is realized.

The polarization directions of the two-dimensional array linear polarized light beams emitted by the two-dimensional optical fiber light source array 1 are the same and are all perpendicular to the grid line direction of the high-linear-density multilayer dielectric film grating I2, and the arrangement direction of the cross sections of the light spots after being diffracted by the high-linear-density multilayer dielectric film grating II3 is the same as that of the high-linear-density multilayer dielectric film grating II3θThe angle leads the arrangement direction of the grating to form an angle (pi/2-theta) with the polarization direction, and in order to ensure the synthesis efficiency of the system, the low-linear-density multilayer dielectric film grating I4 and the low-linear-density multilayer dielectric film grating II 5 are polarization-independent gratings; because the two-dimensional optical fiber light source array 1 emits linearly polarized light, the high-linear-density multilayer dielectric film grating I2 and the high-linear-density multilayer dielectric film grating II3 are polarization gratings.

The device is also suitable for the situation that the two-dimensional optical fiber light source array 1 emits unpolarized light beams, and the corresponding high-linear-density multilayer dielectric film grating I2 and high-linear-density multilayer dielectric film grating II3 are polarization-independent gratings.