阅读说明：本技术 一种阵列光纤与大尺寸石英端帽的熔接装置与方法 (Fusion welding device and method for array optical fiber and large-size quartz end cap ) 是由 张海波 吴梦浩 何兵 雷雨 周军 漆云凤 袁志军 叶韧 于 2021-01-04 设计创作，主要内容包括：一种实现阵列光纤与大尺寸石英端帽熔接的装置,包括二氧化碳激光器、分光镜、光束整形器、高反镜、图像探测模块、阵列光纤及其载具、大尺寸石英端帽及其载具、步进电机、测温仪、计算机；二氧化碳激光器发出的激光束经分光镜分成两束光,其在分别经光束整形器和高反镜后,整形成两束功率密度均匀的条状光斑来加热大尺寸石英端帽的熔接面,通过间接加热和热传导实现目标熔接区域均匀温度场,当熔接区域处温度达到预设温度后,驱动步进电机使阵列光纤匀速平移至熔接区域处与端帽融合叠加,即可实现阵列光纤的一次性熔接。阵列光纤与大尺寸石英端帽熔接完成的阵列光纤端帽有助于优化光谱合成系统的合成光的光束质量和实现合束装置紧凑化和轻量化。(A device for realizing fusion welding of an array optical fiber and a large-size quartz end cap comprises a carbon dioxide laser, a spectroscope, a light beam shaper, a high-reflection mirror, an image detection module, an array optical fiber and a carrier thereof, a large-size quartz end cap and a carrier thereof, a stepping motor, a temperature measuring instrument and a computer; a laser beam emitted by a carbon dioxide laser is divided into two beams of light by a spectroscope, the two beams of light are shaped into two beams of strip-shaped light spots with uniform power density to heat the welding surface of a large-size quartz end cap after passing through a light beam shaper and a high reflection mirror respectively, a uniform temperature field of a target welding area is realized by indirect heating and heat conduction, and when the temperature of the welding area reaches a preset temperature, a stepping motor is driven to enable the array optical fiber to translate to the welding area at a constant speed to be fused and overlapped with the end cap, so that the one-time welding of the array optical fiber can be. The array optical fiber end cap formed by fusing the array optical fiber and the large-size quartz end cap is beneficial to optimizing the beam quality of the synthesized light of the spectrum synthesis system and realizing the compactness and the light weight of the beam combination device.)

1. A fusion splicing apparatus for splicing an array fiber to a large-size quartz end cap, comprising:

the light source shaping module is used for forming two parallel strip-shaped light spots with the same light spot size as the power density and uniform power density on the end cap welding surface of the large-size quartz end cap (8) to be welded, heating the end cap welding surface, and forming a uniform temperature field in a welding area, namely a projection area of the array optical fiber (14) on the end cap welding surface;

and the image detection module is used for realizing alignment and spacing measurement of the array optical fiber (14) and the large-size quartz end cap (8) and checking whether the optical fiber end face of the array optical fiber (14) is flush.

2. The fusion splicing device of the arrayed optical fibers and the large-size quartz end cap according to claim 1, wherein the light source shaping module comprises a carbon dioxide laser (1), a beam splitter (2), a first beam shaper (3), a first high-reflection mirror (5), a second beam shaper (12) and a second high-reflection mirror (13); the carbon dioxide laser (1) is used for generating collimated carbon dioxide single-mode laser and heating the welding surface of the end cap; the beam splitter (2) is a beam splitter with the transmission/reflection ratio of 50/50, and divides the laser output by the carbon dioxide laser (1) into two same laser beams; the first beam shaper (3) and the second beam shaper (12) are both composed of two cylindrical micro-lens arrays and a spherical Fourier lens, the materials of the two beam shapers are ZnSe, and the two split laser circular light spots can be shaped into strip-shaped light spots with uniform power density; the first high-reflection mirror (5) and the second high-reflection mirror (13) are used for changing the direction of the laser beam;

the image detection module is composed of a first CCD camera (6) and a second CCD camera (9) which are vertically arranged, and the imaging directions of the first CCD camera (6) and the second CCD camera (9) are perpendicular to the optical axis of the optical fiber.

3. The fusion apparatus of claim 2, further comprising: the temperature measuring instrument (4) is used for monitoring the temperature of the welding surface of the end cap;

the end cap carrier (7) is used for clamping the large-size quartz end cap (8) and realizing five-dimensional displacement adjustment of the large-size quartz end cap;

the array optical fiber carrier (10) is used for clamping the array optical fibers (14), enabling the optical fibers to be arranged in parallel and realizing five-dimensional displacement adjustment on the optical fibers;

the stepping motor (11) is connected with the array optical fiber carrier (10) and is used for realizing the linear translation of the array optical fiber (14); and the computer (15) is respectively connected with the temperature measuring instrument (4), the first CCD camera (6), the second CCD camera (9) and the stepping motor (11) and is used for controlling the temperature measuring instrument (4) to realize temperature monitoring, processing images collected by the first CCD camera (6) and the second CCD camera (9) and controlling the stepping motor (11) to perform linear displacement.

4. The fusion splice of an arrayed optical fiber and a large-size quartz end cap according to claim 1, wherein the arrayed optical fiber (14) is composed of a plurality of optical fibers, the distance Δ x between each two adjacent optical fibers is arbitrarily variable, and the sizes of the adjacent optical fibers are not equal.

5. The fusion splice of arrayed optical fibers and large-size quartz end caps of claim 4, wherein the arrayed optical fibers (14) are in a single row or two rows.

6. A method of fusion splicing an arrayed optical fiber to a large-sized quartz end cap according to claim 2, comprising the steps of:

clamping and fixing the array optical fibers (14) to be welded through an array optical fiber carrier (10) to enable the array optical fibers (14) to be arranged in parallel; clamping and fixing a large-size quartz end cap (8) to be welded through an end cap carrier (7);

controlling a first CCD camera (6) and a second CCD camera (9) to image the array optical fiber (14) and the large-size quartz end cap (8) through a computer (15), checking whether the optical fiber end faces of the array optical fiber (14) are flush, and finishing alignment and distance measurement of the array optical fiber (14) and the large-size quartz end cap (8) by adjusting an array optical fiber carrier (10) and an end cap carrier (7);

a carbon dioxide laser (1) is turned on to generate a collimated laser beam, the collimated laser beam is divided into two same laser beams by a beam splitter (2), the two same laser beams respectively pass through a first beam shaper (3), a first high-reflection mirror (5), a second high-reflection mirror (13) and a second beam shaper (12) and then are changed into two strip-shaped light spots with uniform power density, the two strip-shaped light spots are used for heating the welding surface of an end cap, and a uniform temperature field is formed at a welding area;

monitoring the real-time temperature of the welding area by using a temperature measuring instrument (4), setting a stepping motor (11) at a proper translation speed and distance after the preset temperature is reached, and driving the stepping motor (11) to realize accurate linear translation of the array optical fiber (14);

and fifthly, closing the carbon dioxide laser (1) after the movement is finished, namely finishing the one-time fusion of the array optical fiber (14) and the large-size quartz end cap (8).

Due to the fact that the optical axis of the irradiation heating light beam and the off-axis structure of the array optical fiber are arranged, the array optical fiber end cap which is welded can be heated again, welding stress can be released, and welding quality is improved.

Technical Field

The invention belongs to the field of optical fiber end cap welding, and particularly relates to a welding device and method for an array optical fiber and a large-size quartz end cap.

Background

The high-brightness optical fiber laser has wide application prospect in the fields of industry, medical treatment, national defense and the like. The output power of the single-path single-mode fiber laser has theoretical limit due to the limitation of factors such as nonlinear effect, mode instability effect, material damage characteristic and the like. The multi-beam synthesis technology is an important technical approach for realizing high-power and high-beam-quality laser output, and the specific beam combination method can not only improve the output laser power, but also ensure that the output laser has excellent beam quality. The spectrum synthesis technology has the advantages of good output beam quality, no requirement on sub-beam phase, simple and stable structure and the like, and shows no replaceable important application value. Theoretically, the spectrum synthesis can improve the output power of laser by increasing the number of paths proportionally under the condition of keeping the quality of an input laser beam, and realize the scaling amplification of the brightness of a synthesized beam. However, in an actual synthesis system, the beam quality of the synthesized light is inferior to that of the laser input by a single optical fiber, which is mainly influenced by factors such as disturbance of the laser array, aberration of the conversion lens, thermal distortion of the diffraction grating, line width of the array light source, and the like.

Because the single-path optical fiber output head needs to be mechanically clamped and water-cooled in the spectrum beam combining device, the distance delta x between adjacent optical fibers cannot be reduced without limit, and the beam combining device cannot be compacted and lightened, so that the application of a high-brightness optical fiber laser on a mobile platform is limited.

The array optical fiber end cap formed by fusing the array optical fiber and the large-size quartz end cap is beneficial to optimizing the beam quality of the synthesized light of the spectrum synthesis system and realizing the compactness and the light weight of the beam combination device. The array optical fiber end cap is a key device for coupling the optical fiber laser array to the spectrum synthesis system and realizing the compact high-brightness laser light source.

Disclosure of Invention

The invention provides a fusion splicing device and a fusion splicing method for an array optical fiber and a large-size quartz end cap, which are used for overcoming the defects of the prior art.

The invention realizes the technical purpose through the following technical means:

a fusion splicing device of an array optical fiber and a large-size quartz end cap is characterized by comprising:

the light source shaping module is used for forming two parallel strip-shaped light spots with the same light spot size and power density and uniform power density on the welding surface of the end cap of the large-size quartz end cap to be welded, heating the welding surface of the end cap, and forming a uniform temperature field in a welding area, namely a projection area of the array optical fiber on the welding surface of the end cap;

the image detection module is used for realizing alignment and distance measurement of the array optical fiber and the large-size quartz end cap and checking whether the optical fiber end faces of the array optical fiber are flush;

the light source shaping module comprises a carbon dioxide laser, a beam splitter, a first beam shaper, a first high-reflection mirror, a second beam shaper and a second high-reflection mirror; the carbon dioxide laser is used for generating collimated carbon dioxide single-mode laser and heating the welding surface of the end cap; the beam splitter is a beam splitter with the transmission/reflection ratio of 50/50, and divides the laser output by the carbon dioxide laser into two same laser beams; the first beam shaper and the second beam shaper are both composed of two cylindrical micro-lens arrays and a spherical Fourier lens, and are made of ZnSe, so that the two divided laser circular spots can be shaped into strip-shaped spots with uniform power density; the first high-reflection mirror and the second high-reflection mirror are used for changing the direction of the laser beam; (ii) a

The image detection module consists of a first CCD camera and a second CCD camera which are vertically arranged, and the imaging directions of the first CCD camera and the second CCD camera are both vertical to the optical axis of the optical fiber;

the fusion splicing device of the array optical fiber and the large-size quartz end cap is characterized by further comprising:

the end cap carrier can be divided into a two-dimensional adjustable mirror bracket and a translation platform base which are used for clamping and fixing the end cap and realizing five-dimensional displacement adjustment, namely the two-dimensional displacement adjustment of the pitching and the azimuth of the two-dimensional adjustable mirror bracket and the three-dimensional displacement adjustment of the translation platform base; (ii) a

The array optical fiber carrier is used for clamping and fixing array optical fibers and realizing five-dimensional displacement adjustment of the array optical fibers and can be divided into three parts, namely a pressing plate clamp holder, a two-dimensional adjustable mirror bracket and a translation platform base, wherein the number of layers of the pressing plate clamp holder and a V-shaped groove array are customized according to needs to clamp and fix the array optical fibers, the positioning precision of the pressing plate clamp holder for fixing the optical fibers can reach +/-1 micron, so that the optical fibers have very high parallelism, and the array optical fibers are arranged in parallel; (ii) a

The stepping motor is arranged and fixed on the array optical fiber carrier and used for realizing the linear translation of the array optical fiber;

and the computer is respectively connected with the temperature measuring instrument, the first CCD camera, the second CCD camera and the stepping motor, and is used for controlling the temperature measuring instrument to realize temperature monitoring, processing images acquired by the first CCD camera and the second CCD and controlling the stepping motor to perform linear displacement.

The array optical fiber is composed of a plurality of optical fibers, the distance delta x between every two adjacent optical fibers can be changed randomly, and the sizes of the adjacent optical fibers can be unequal.

The array optical fiber is in a single row or two rows. In the welding area, namely the projection area of the array optical fiber on the welding surface of the end cap of the large-size quartz end cap, the distances from the two beams of strip-shaped light spots to the projection of the array optical fiber are equal and can be larger than the width of the strip-shaped light spots.

When the number of the rows of the array optical fibers is two, the array optical fibers are symmetrically arranged about the center of the end cap.

According to one embodiment of the invention, a beam shaper composed of two cylindrical microlens arrays (MLA1 and MLA2) and a spherical Fourier Lens (FL) which are made of ZnSe shapes the split round light spots, so that flat-top homogenization of collimated Gaussian beams is realized, and strip-shaped light spots with uniformly distributed power are obtained. The light spot length L on the focal plane of the spherical Fourier lens is as follows:

wherein f is_FLIs the focal length of the lens (FL), f_MLA1And f_MLA2The focal lengths of the two cylindrical microlens arrays are respectively, the MLA2 cylindrical microlens array is positioned between the two optical elements, the distance between the two cylindrical microlens arrays is d, the lens units have the same size and are all P_MLA(ii) a Under the conditions determined by the optical elements, strip-shaped light spots with different lengths can be realized by changing the size of d (peri-lobe, congratulatory euphoria, Huangzhongya, etc. in the prior art, design and experimental research of a laser homogenization system based on a cylindrical microlens array, laser and infrared, 2020,50(04): 486-. The end cap welding surface is heated through the two strip-shaped light spots which are parallel to each other and have uniformly distributed power, the temperature distribution of the area between the two light spots is approximately in one-dimensional gradient distribution, the temperature distribution is symmetrical about the center of the end cap, the temperature difference between the center and the edge of the welding area is smaller in the diameter range of an optical fiber cladding, the influence on the welding quality is smaller, an even temperature field can be formed in the welding area, and the welding of the array optical fiber and the large-size quartz end cap is facilitated.

According to one embodiment of the present invention, the fusion method comprises the steps of:

firstly, clamping and fixing array optical fibers to be welded by using a pressing plate holder customized as required, so that the array optical fibers are arranged in parallel, and the pressing plate holder can be arranged on an array optical fiber carrier in a magnetic attraction manner; clamping and fixing a large-size quartz end cap to be welded by using an end cap carrier;

secondly, the first CCD camera and the second CCD camera are controlled by a computer to image the array optical fiber and the large-size quartz end cap, whether the optical fiber end faces of the array optical fiber are flush or not is checked, the alignment and the distance measurement of the array optical fiber and the large-size quartz end cap are completed by adjusting the array optical fiber carrier and the end cap carrier, and then the stepping motor is driven to drive the array optical fiber to translate to enable the distance between the array optical fiber and the large-size quartz end cap to be proper (about 100 micrometers), and the distance is kept unchanged in each fusion experiment;

turning on a carbon dioxide laser to generate a collimated laser beam with proper power, dividing the collimated laser beam into two same laser beams through a beam splitter, respectively passing through a first beam shaper, a first high-reflection mirror, a second high-reflection mirror and a second beam shaper to form two strip-shaped light spots with proper spacing and uniform power density, wherein the two strip-shaped light spots are required to keep consistent optical paths after passing through the beam shapers and are used for heating the welding surface of the end cap to form a uniform temperature field at the welding area, and the spacing between the strip-shaped light spots and the array optical fiber is larger than the width of a linear light spot;

monitoring the real-time temperature of the fusion area by using a temperature measuring instrument, setting a stepping motor at a proper translation speed and distance after the preset temperature is reached, driving the stepping motor to realize accurate linear translation of the array optical fiber, wherein the difference between the translation distance of the stepping motor and the distance between the array optical fiber and the large-size quartz end cap is the fusion length;

and fifthly, closing the carbon dioxide laser after the movement is finished, namely finishing the one-time fusion of the array fiber and the large-size quartz end cap.

Due to the fact that the optical axis of the irradiation heating light beam and the off-axis structure of the array optical fiber are arranged, the array optical fiber end cap which is welded can be heated again, welding stress can be released, and welding quality is improved.

The invention has the beneficial effects that:

the welding method has the following technical advantages: firstly, the optical fiber array prearrangement technology, the optical axis of the array optical fiber can have high parallelism by a pressing plate holder customized according to requirements, namely the array optical fiber is arranged in parallel; the double-beam coupling uniform heating technology is characterized in that two parallel strip-shaped light spots with uniform power density are used for heating a non-target area, a welding area is indirectly heated in a heat conduction mode, a uniform temperature field of the welding area is realized, welding of the array optical fiber end cap is facilitated, the array optical fiber end cap after welding can be reheated, welding stress can be released, and welding quality can be improved; the fiber array has strong scale expansibility, the uniform temperature field of a welding area is realized by heating the end caps through the strip-shaped light spots after the light beams are shaped, the welding of the array fibers and the large-size quartz end caps with the adjacent fiber spacing delta x being variable at will, the sizes of the adjacent fibers being unequal, and the number of rows of the adjacent fibers being two can be realized, and the array fibers have strong scale expansibility, so that the scale of the array fibers to be welded can be enlarged when the range of the uniform temperature field is enlarged;

the method can provide reference for the optimal design of a laser array part in a high-brightness spectrum synthesis system; compared with the mode that a plurality of optical fiber end caps are arranged into a linear array to realize laser array output, the array optical fiber end cap formed by welding the array optical fiber and the large-size quartz end cap has the advantages of higher integration level and flexibility and variability of the array optical fiber;

description of the drawings:

FIG. 1 is a schematic diagram of a fusion connection structure of an array fiber and a large-size quartz end cap according to the present invention.

FIG. 2 is a schematic diagram of the optical path of the array fiber fused with a large-size quartz end cap according to the embodiment of the present invention.

Fig. 3 is a front view of a fused face of an end cap according to an embodiment of the present invention, wherein a is a single row of arrayed optical fibers and b is two rows of arrayed optical fibers.

Fig. 4 is a schematic diagram of a beam shaper.

FIG. 5 is a schematic view of a platen holder for arrayed optical fibers.

FIG. 6 is a schematic view of a platen holder for an array of fibers in two rows.

Reference numerals:

the device comprises a carbon dioxide laser 1, a beam splitter 2, a first beam shaper 3, a temperature measuring instrument 4, a first high-reflection mirror 5, a first CCD camera 6, an end cap carrier 7, a large-size quartz end cap 8, a second CCD camera 9, an array optical fiber carrier 10, a stepping motor 11, a second beam shaper 12, a second high-reflection mirror 13, an array optical fiber 14 and a computer 15.

Detailed Description

In order to make the aforementioned features and effects of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather construed as limited to the embodiments set forth herein.

The following describes in detail an apparatus for implementing fusion splicing of an array optical fiber and a large-size quartz end cap according to an embodiment of the present invention with reference to the accompanying drawings.

Referring to fig. 1, fig. 2 and fig. 3, an apparatus for implementing fusion splicing of an array fiber and a large-sized quartz end cap according to an embodiment of the present invention includes: the device comprises a carbon dioxide laser 1, a beam splitter 2, a first beam shaper 3, a temperature measuring instrument 4, a first high-reflection mirror 5, a first CCD camera 6, an end cap carrier 7, a large-size quartz end cap 8, a second CCD camera 9, an array optical fiber carrier 10, a stepping motor 11, a second beam shaper 12, a second high-reflection mirror 13, an array optical fiber 14 and a computer 15.

Specifically, the method for realizing fusion splicing of the array optical fiber and the large-size quartz end cap comprises the following steps:

firstly, clamping and fixing array optical fibers 14 to be welded by using a pressing plate holder customized as required (the distance delta x between adjacent optical fibers is randomly variable, the sizes of the adjacent optical fibers can be unequal as shown in figure 5, and the number of rows can be two as shown in figure 6), so that the array optical fibers 14 are arranged in parallel, and the pressing plate holder can be arranged on an array optical fiber carrier 10 in a magnetic attraction manner; clamping and fixing a large-size quartz end cap 8 to be welded through an end cap carrier 7;

a CCD camera can use a telecentric lens and needs a proper view field and an illumination light source; the computer 15 is used for controlling the first CCD camera 6 and the second CCD camera 9 to image the array optical fiber 14 and the large-size quartz end cap 8, checking whether the optical fiber end surface of the array optical fiber 14 is flush, adjusting the array optical fiber carrier 10 and the end cap carrier 7 to finish the alignment and the distance measurement of the array optical fiber 14 and the large-size quartz end cap 8, and driving the stepping motor 11 to enable the distance between the two to be proper (in order to avoid errors caused by reciprocating motion of the stepping motor, the absolute displacement command of the stepping motor can be adopted to control the stepping motor, wherein the proper distance is kept unchanged in a series of fusion welding experiments);

thirdly, turning on the carbon dioxide laser 1 to generate proper workThe collimated laser beam with the ratio is divided into two same laser beams after passing through a beam splitter 2, the two same laser beams respectively pass through a first beam shaper 3, a first high-reflection mirror 5, a second high-reflection mirror 13 and a second beam shaper 12 and then are changed into two strip-shaped light spots with proper distance and uniform power density, wherein the optical paths of the two laser beams after passing through a cylindrical lens need to be kept consistent, the two strip-shaped light spots are used for heating an end cap welding surface and forming a uniform temperature field at a welding area, and the maximum number of the welded fibers of a single-row array fiber is N_MAXL/D, wherein L is the length of the strip-shaped light spot, and D is the diameter of the optical fiber;

monitoring the real-time temperature of the welding area by using a temperature measuring instrument 4, setting a stepping motor at a proper translation speed and distance after the preset temperature is reached (the translation speed and the distance need to be correspondingly set according to different optical fiber sizes), and driving the stepping motor to drive the array optical fiber 14 to perform linear translation, wherein the difference between the translation distance of the stepping motor 11 and the distance between the array optical fiber 14 and the large-size quartz end cap 8 is the welding length;

and fifthly, closing the carbon dioxide laser 1 after the movement is finished, namely finishing the one-time fusion of the array optical fiber 14 and the large-size quartz end cap (8).

Due to the fact that the optical axis of the irradiation heating light beam and the off-axis structure of the array optical fiber 14 are arranged, the array optical fiber end cap which is welded can be heated again, welding stress can be released, and welding quality is improved.

According to one embodiment of the invention, the size of the optical fiber to be welded is set to be 20/250 micrometers, the array optical fiber is in a single row, the central wavelength of pulse laser output by a carbon dioxide laser is 10.6 micrometers, the output laser power is proper, the distance between linear light spots is proper length, the distance between the array optical fiber and the quartz end cap is made to be 100 micrometers, the stepping motor is driven to translate for 130 micrometers, the translation speed is 75 micrometers per second, after the laser is heated for proper time, the stepping motor is driven to drive the array optical fiber to perform accurate linear translation when the temperature of a welding area measured by a temperature measuring instrument is about 1700 ℃, and after the translation is completed, the laser is turned off, so that the one-time welding of the array optical fiber and the quartz end cap with the large size is completed.

Another embodiment of the invention is to place a beam shaping lens group behind the carbon dioxide laser, and the lens group can shape the collimated carbon dioxide laser beam into a collimated strip-shaped light spot with uniform power density to replace a beam shaper, so that the debugging steps of an experimental device and a welding experiment can be simplified.

The present invention is not limited to the embodiments described, and any obvious improvements, substitutions or modifications made to the essential contents of the present invention belong to the protection scope of the present invention.