High-power glued optical fiber combiner and preparation method thereof

Abstract

The invention discloses a high-power glued optical fiber combiner and a preparation method thereof, the high-power glued optical fiber combiner is characterized in that the high-power glued optical fiber combiner comprises a non-tapering input optical fiber bundle, an output optical fiber end cap and infrared optical glue, the non-tapering input optical fiber bundle penetrates into a metal insertion core, the non-tapering input optical fiber bundle and the output optical fiber end cap are glued through the infrared optical glue, and the output optical fiber end cap is connected with the metal insertion core. The infrared optical glue gluing part is packaged and fixed through a quartz glass tube. The preparation method comprises the following steps: preparing an input optical fiber bundle for energy input of high-power optical fiber laser; a step of preparing an output fiber end cap for energy output of the high-power fiber laser; finally, the input optical fiber bundle and the output optical fiber end cap are glued through infrared optical glue, and the high-power glued type optical fiber beam combiner meeting the requirement for middle-infrared band high-power laser transmission is obtained, and the high-power glued type optical fiber beam combiner has the advantages of being efficient, stable and capable of improving the infrared optical fiber beam combining power threshold value.

Description

Technical Field

[0001] The present invention belongs to the technical field of fiber beam combining, and particularly relates to a high-power glued fiber beam combiner and a preparation method thereof. Background Art

[0002] With the development of modern communication and fiber laser technologies, the demand for high-power laser transmission systems has gradually increased. In high-power laser applications, the power-carrying capacity of a single fiber is limited. To meet the demand for high-power output, multiple fibers must be used to combine energy. Therefore, the Taper Fused Fiber Bundle (TFB) came into being. TFB has a wide range of applications in fiber optic communication, laser systems, medical imaging, and optical sensing. Its principle is based on combining multiple fibers into a smaller fiber unit capable of transmitting multiple optical channels through the fused taper technique. For example, in the Chinese invention patent "Mid-wave and long-wave infrared integrated fiber beam combiner and its preparation method" (publication number CN115113335B), it is formed by tightly packing and fusing m mid-wave infrared fibers and n long-wave infrared fibers, including 1 tapered output end and m + n circular input ends arranged dispersedly. The beam combining efficiency is high, but due to the fused taper, the power density increases, and heat accumulation leads to low power. In the Chinese utility model patent "A mid-infrared beam combiner" (publication number CN 217036310U), multiple chalcogenide fibers and a chalcogenide tube form a chalcogenide fiber bundle, and the fiber bundle and the output fiber are fixed in a metal sleeve at the same time. Its advantages are small size and high stability, but it does not show power advantages.

[0003] Currently, the more common types of infrared fiber beam combiners are: 3*1, 4*1, 7*1, 19*1, etc. However, this fiber beam combining technology mainly relies on the method of fused taper. Its preparation method is to taper multiple fibers and then fuse an output fiber. Such a preparation method of tapering multiple fibers simultaneously has disadvantages such as increased optical power density, heat accumulation, mode field mismatch, and mode coupling in each taper region. At the same time, during the process of tapering multiple fibers, due to the limitations of process complexity and equipment accuracy, it is impossible to accurately control key parameters such as the taper angle, length, shape, and ratio. This lack of control leads to defects easily generated in the fiber during the tapering process, such as surface roughness, geometric asymmetry, and internal stress concentration. These defects not only increase the transmission loss of the fiber but also significantly reduce its damage threshold, seriously affecting the stability of the fiber in a high-power laser environment. In addition, the coupling efficiency between multiple fibers also decreases due to uneven tapering, further limiting the improvement of the power threshold of fiber lasers. Summary of the Invention

[0004] The present invention aims to solve the technical problems existing in the tapering process of multiple optical fibers. By adopting the tapering process of a single large-core preform instead of the traditional tapering process of multiple optical fibers, a high-power glued fiber combiner and its preparation method are provided, which are efficient, stable and can increase the power threshold of fiber beam combination. Specifically, the present invention solves the problems that the tapering angle, length, shape and ratio cannot be accurately controlled during the tapering process of multiple optical fibers, and avoids problems such as an increase in fiber defects, an increase in loss and a decrease in damage threshold caused by uneven tapering, thereby realizing a higher-power fiber beam combination output and providing reliable technical support for improving the performance of high-power fiber lasers.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a high-power glued fiber combiner, which includes an untapered input fiber bundle, an output fiber end cap and an infrared optical adhesive. The untapered input fiber bundle penetrates into a metal ferrule, and the untapered input fiber bundle and the output fiber end cap are glued through the infrared optical adhesive. The glued part of the infrared optical adhesive is encapsulated and fixed by a quartz glass tube.

[0006] Further, the infrared optical adhesive is composed of elements As, S, I and Se. The atomic percentage range of As is 10-50 at%, the atomic percentage range of S is x; the atomic percentage range of Se is y, where x + y = 10-68 at% and y > 0; the atomic percentage range of I is 0-35 at%. The refractive index range of the infrared optical adhesive is 2.11-2.24.

[0007] Further, the untapered input fiber bundle is composed of 7 large-mode-area As 2 S 3 optical fibers arranged in a regular hexagon.

[0008] Further, the output fiber end cap is made by tapering a GeAsS preform.

[0009] The present invention also provides a preparation method for the above high-power glued fiber combiner, which includes the following steps: Step 1, prepare an input fiber bundle for the energy input of high-power fiber lasers; Step 2, prepare an output fiber end cap for the energy output of high-power fiber lasers; Step 3, glue the input fiber bundle and the output fiber end cap through the infrared optical adhesive to obtain a high-power glued fiber combiner that meets the requirements of high-power laser transmission in the mid-infrared band.

[0010] Further, Step 1 is specifically as follows: Prepare 7 large-mode-area As 2 S 3Optical fiber, prepare a metal ferrule with a diameter size equal to the long side after arranging 7 optical fibers in a regular hexagon; (2)Cluster and tightly and symmetrically arrange 7 As 2 S 3 optical fibers, insert them into the metal ferrule, and evenly apply a high-temperature curing adhesive between the arranged As 2 S 3 optical fibers and the metal ferrule to fix the position of the As 2 S 3 optical fibers in the ferrule, and put the assembled fiber bundle into an oven for curing; (3)Prepare the end face of the cured fiber bundle for grinding and polishing. Through the processes of rough grinding, medium grinding, fine grinding, and polishing, an input fiber bundle with reduced surface scratches and a flat end face is obtained.

[0011] Furthermore, step 2 is specifically as follows: (1)Prepare a GeAsS large-core preform and cut the required length. By controlling the heating temperature of the temperature zones of the drawing tower, a tapered zone is formed at the front end of the large-core preform. At the same time, the inner core at the rear end of the large-core preform is made into a shape matching the outer diameter of the input fiber bundle to obtain a GeAsS end cap; (2)Grind one end of the GeAsS end cap that is glued to the input fiber bundle. During the grinding process, use gradually refined abrasive papers for end face grinding to finally obtain an output fiber end cap.

[0012] Furthermore, step 3 is specifically as follows: (1)Evenly apply an infrared optical adhesive with good transmittance in the infrared spectral range on the contact surface between the input fiber bundle and the output fiber end cap and completely cover it; (2)Encapsulate the glued part of the input fiber bundle and the output fiber end cap with a quartz glass tube, and fill the gap between the quartz glass tube and the metal ferrule with glue to obtain a high-power glued fiber combiner.

[0013] Compared with the prior art, the advantages of the present invention are as follows: In a high-power glued fiber combining technology disclosed in the present invention, multiple optical fibers are tightly and neatly arranged to form a fiber bundle, and there is no need to perform fusion tapering treatment on the optical fibers, thus effectively solving problems such as reduced power density, mode field mismatch, and decreased fiber damage threshold caused by uneven tapering in the traditional multi-fiber tapering process. In addition, the present invention uses an SMA905 metal ferrule to fix the arrangement shape and position of the fiber bundle, ensuring that the fiber bundle has high consistency and a tightly arranged structure after end face grinding, significantly improving the mechanical stability and optical performance of the fiber combiner, and providing a reliable guarantee for the stable operation of high-power fiber lasers.

[0014] Compared with the traditional fiber beam combining and coupling technology based on fused tapering, the present invention proposes an innovative glued fiber beam combining scheme, which can effectively improve the integration degree of the fiber bundle, optimize the arrangement structure and joining method of the optical fibers. Specifically, by introducing the refractive index matching principle, the present invention maximizes the optical compatibility at the connection interface between the fiber bundle and the end cap, effectively reduces the end face reflection loss, and improves the optical transmission efficiency at the same time.

[0015] In the present invention, a pure liquid optical glue material is adopted, which has good fluidity and self - adaptability, can be evenly filled between the fiber bundle and the end face of the end cap, thus ensuring the high - precision docking and tight adhesion between the fiber bundle and the end cap. This liquid optical adhesive forms a seamless optical interface between the optical fiber end faces, which can effectively reduce the stress and optical transmission instability caused by the mismatch of thermal expansion coefficients. In addition, the characteristics of the liquid optical glue material enable it to be widely compatible with different types of glass optical fibers, without the matching problem caused by the difference in thermal expansion coefficients, and a higher transmission power threshold can be obtained, ensuring that the system can operate stably at a higher power without overheating or damage.

[0016] The optical adhesive of the present invention has good transmittance in the infrared spectrum range. At the same time, the optical adhesive has a high refractive index and better matching in the infrared field. The optical adhesive of the present application can effectively reduce the Fresnel reflection between glasses of different refractive index materials, and can increase the maximum power threshold of the glass, thereby improving the glass transmission efficiency.

[0017] In summary, the present invention provides a high - power glued fiber beam combiner and its preparation method. By closely arranging and efficiently integrating multiple untapered optical fibers, the high - performance synthesis and high - power transmission of multiple lasers are realized. This technology effectively solves the performance limitations caused by problems such as increased optical power density, thermal accumulation effect, mode field mismatch, and mode coupling in the traditional fiber beam combining process, increases the power threshold of fiber beam combining, and especially realizes long - term stable operation in high - power fiber lasers. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a high - power glued fiber beam combiner, and the markings in the figure are as follows: 1. Untapered input fiber bundle; 2. Output fiber end cap; 3. Infrared optical glue; 4. Metal ferrule; 5. Quartz glass tube; Figure 2 It is a physical diagram of a high - power glued fiber beam combiner; Figure 3 It is an arrangement end - face diagram of a fiber bundle with 7 optical fibers closely arranged on the SMA905 metal ferrule; Figure 4 It is a Fresnel reflection loss diagram of the theoretical calculation of the input fiber bundle and the output fiber end cap end faces; Figure 5 Efficiency improvement diagram after gluing the input optical fiber bundle and the output optical fiber end cap; Figure 6 Efficiency diagram of the input power and output power of each path of the fiber beam combiner; Figure 7 Power threshold of a single path of the fiber beam combiner at 4.7 μm; Figure 8 Efficiency stability diagram after the fiber beam combiner is packaged. Specific implementation mode

[0019] The present invention will be further described in detail below in conjunction with the embodiments with reference to the drawings.

[0020] Specific Embodiment 1. A high-power glued fiber beam combiner.

[0021] A high-power glued fiber beam combiner, as Figure 1 and Figure 2 shown, includes an untapered input optical fiber bundle 1, an output optical fiber end cap 2, and an infrared optical glue 3. The untapered input optical fiber bundle 1 penetrates into an SMA905 metal ferrule 4, and the end face is polished to be smooth and flat. The untapered input optical fiber bundle 1 and the output optical fiber end cap 2 are glued with the infrared optical glue 3, and the glued part is fixed with a quartz glass tube 5 to make the package stable.

[0022] The infrared optical glue 3 contains elements As, S, I, and Se. The atomic percentage range of As is 10 - 50 at%, the atomic percentage range of S is x; the atomic percentage range of Se is y, where x + y = 10 - 68 at% and y > 0; the atomic percentage range of I is 0 - 35 at%. The refractive index range of the infrared optical glue 3 is 2.11 - 2.24. Its preparation method is as follows: Each element of the optical adhesive is put into a glass tube according to the proportion, the opening of the glass tube is opened, and the glass tube is evacuated; the glass tube is placed in a rocking furnace for rocking heating until all the elements in the glass tube are melted into a liquid state, and then the liquid substance in the glass tube is cooled to obtain the infrared optical glue.

[0023] Performance test of the prepared infrared optical glue: Glue glasses with different refractive indexes using the above-mentioned As - S - Se - I infrared optical glue: Prepare four ZnSe wafers and two As 2 S 3 wafers. Sandwich one As 2 S 3 wafer between two of the ZnSe wafers and fix it. Then, test its transmittance through a 10.6 μm laser. The other two ZnSe wafers are respectively pasted to the second As 2 S 3On both sides of the wafer, a 10.6 μm laser was used to test its transmittance. After testing, the combined transmittance using the As-S-Se-I optical adhesive increased by approximately 15%, indicating that the As-S-Se-I optical adhesive can effectively reduce light loss caused by Fresnel reflection at the interface between chalcogenide glass and other low refractive index optical materials in the far infrared range.

[0024] The above infrared optical adhesive is composed of elements arsenic (As), sulfur (S), selenium (Se), and iodine (I). Among them, the arsenic component acts as a glass modifier, the S component helps the glass to be in a liquid state, the Se component optimizes the glass network, and due to its relatively strong ionic properties, the I element can break some of the covalent bond networks, reduce the glass viscosity, and help the glass to be in a liquid state. That is, the optical adhesive of this application is in a liquid state, with properties between ordinary inorganic glass and organic polymers. It has a viscosity greater than 1000 Pa·s at room temperature, a low Tg, and has fluidity at higher temperatures. Its fluidity changes with temperature, and the fluidity and viscosity of the adhesive can be controlled. If the two optical elements are not pasted in place, the fluidity of the optical adhesive can be improved by changing the temperature, and after readjusting the optical elements, they can be pasted; at the same time, the liquid state of this optical adhesive is more conducive to the operation during gluing, and there are less likely to be air gaps when bonding optical elements or lens lenses.

[0025] The above non-tapered input fiber bundle 1 is composed of 7 large mode area As 2 S 3 fibers arranged in a regular hexagon. The output fiber end cap 2 is made by cutting a 5 cm length from a GeAsS preform with a diameter of 4 mm and tapering it. The quartz glass tube 5 is made of quartz, with an inner diameter of 4 mm and an outer diameter of 5 mm, and is used to match the outer diameter of the SMA905 metal ferrule 4 (<4 mm) and the outer diameter of the large core end of the output fiber end cap 2 (<4 mm). The physical diagram of the fabricated glued fiber combiner is as Figure 2 shown.

[0026] Specific Embodiment 2: A preparation method of a high-power glued fiber combiner, comprising the following steps: Step 1: Prepare an input fiber bundle for the energy input of high-power fiber lasers, comprising the following steps: (1) Prepare 7 large mode area As 2 S 3 fibers with a core diameter of 130 μm and a cladding diameter of 300 μm, and prepare an SMA905 metal ferrule 4 with a diameter size equal to the long side after arranging the 7 fibers in a regular hexagon; (2) Arrange the 7 As 2 S 3 fibers in a cluster tightly and symmetrically, and insert them into the SMA905 metal ferrule 4, as Figure 3As shown in the figure, a high-temperature curing adhesive 353ND is evenly applied between the arranged optical fibers and the metal ferrule 4 to fix the position of the optical fiber bundle in the ferrule, so that the optical fiber bundle is arranged compactly and neatly. Then, the assembled optical fiber bundle is placed in an oven for curing. Set the curing time and temperature as follows: heat up from 30°C to 90°C in 30 minutes, keep the temperature at 90°C for 5 hours, and then cool down from 90°C to 30°C in 90 minutes. (3)Prepare the end face of the cured optical fiber bundle for grinding and polishing. The grinding machine used in the experiment is a Japanese Seiko Electronics grinding machine (SEIKOH GIKEN, SEP-550, Japan) (rotation speed 70 r / min). By changing the parameters of grinding and polishing time and the particle size of the grinding and polishing sandpaper, a better end face effect can be achieved. The grinding and polishing sandpaper is pasted on a rubber pad with water, and the SMA905 metal ferrule 4 is fixed on the fixture plate by a screw. Through the processes of rough grinding, medium grinding, fine grinding, and polishing, the surface of the optical fiber bundle gradually changes from rough and uneven to having fewer surface scratches and a flat end face. The specific process is as follows: First, use diamond grinding sandpaper with a grit size of 9 μm for 40 s under a grinding pressure of 0.2 MPa. After rough grinding, check the end face with an end face detector, and the end face has obvious scratches and is rough. Then, use diamond grinding sandpaper with a grit size of 6 μm for 60 s under the same grinding pressure. After medium grinding, the end face scratches are significantly reduced, and the surface roughness is further improved. Then, use diamond grinding sandpaper with grit sizes of 3 μm and 1 μm for fine grinding, and grind for 60 s and 90 s respectively under a grinding pressure of 0.2 MPa. The end face of the obtained optical fiber bundle is clear and flat, and the contour and end face morphology can be seen. Finally, use ADS polishing sandpaper with a grit size of 0.02 μm for polishing to obtain an input optical fiber bundle with a smooth and flat end face. Performance test of the input optical fiber bundle: Test the input optical fiber bundle under a 1550 nm laser light source. The transmission efficiency of all 7 optical fibers is above 69%. The experiment proves that the 7 optical fibers are closely arranged, the end face is flat and smooth after grinding, and the stability is high.

[0027] Step 2: Prepare the output optical fiber end cap 2 for the energy output of high-power fiber lasers, including the following steps: (1)Prepare a GeAsS large-core preform, cut a 5 cm length, and by controlling the heating temperature of the temperature zones of the drawing tower (slowly heating up, the temperature range for the preform to form a cone is between 320°C and 365°C), make the front end of the large-core preform form a suitable cone zone length (3 - 5 cm). At the same time, make the inner core at the rear end of the large-core preform into a shape matching the outer diameter of the input optical fiber bundle (the inner diameter of the rear-end inner core is 660 - 880 μm larger than the outer diameter of the input optical fiber bundle) to obtain a GeAsS end cap, so as to ensure that the light transmitted by the optical fiber can accurately enter the end cap and avoid position deviation. (2)The end of the polishing end cap that is glued to the input optical fiber bundle. During the polishing process, the end face is polished using progressively finer abrasive papers, and finally, the output optical fiber end cap 2 is obtained. Ensure that the polished end face has no scratches or burrs, thereby minimizing light loss and reflection to the greatest extent and improving the optical transmission efficiency between the optical fiber and the end cap. Performance test of the output optical fiber end cap 2: It is tested under a 1550 nm laser light source, and the transmission efficiency (the ratio of output power to input power) of the output optical fiber end cap 2 reaches 55%, which is proved by experiments to be in line with the theoretical calculation results.

[0028] Step 3: Gluing of the input optical fiber bundle and the output optical fiber end cap 2. The glued optical fiber bundle can meet the high-power laser transmission in the mid-infrared band, including the following steps: (1)Evenly apply the infrared optical glue 3 on the contact surface between the input optical fiber bundle and the output optical fiber end cap 2, and ensure that the infrared optical glue 3 completely covers it, but do not overdo it to avoid bubbles or impurities interfering with the beam transmission. The above optical adhesive has good transparency in the infrared spectral range; (2)Package the glued input optical fiber bundle and the output optical fiber end cap 2 with a quartz glass tube 5 with an outer diameter of 5 mm and an inner diameter of 4 mm. The quartz glass tube 5 of this size can match the large-core end of the output optical fiber end cap 2 and the outer diameter of the SMA905 metal ferrule 4. First, isolate the glued area from the air with silicone sealant (Kafuter), then put the quartz glass tube 5 over the glued area, and finally fill the gap between the quartz glass tube 5 and the SMA905 metal ferrule 4 with glue to obtain a high-power glued optical fiber combiner.

[0029] Specific Example Three: Comparative Experiment 1. Regarding the Fresnel reflection of the end face Performance test of the high-power glued optical fiber combiner: The Fresnel reflection of the end face of the input optical fiber bundle and the large-core end face of the output optical fiber end cap 2 is theoretically calculated. In the control group, the optical fiber bundle and the end cap are glued in the air, and the preparation method is the same as that of the high-power glued optical fiber combiner in Specific Example Two, except that the infrared optical glue 3 is omitted. The results are as Figure 4 shown. When the refractive index n of the air in the control group is 1, its Fresnel reflection is 48.9%. Without considering other transmission losses, the transmission efficiency is 51.1%; when glued with the infrared optical glue 3, that is, when the refractive index n of the infrared optical glue 3 is 2.1, its Fresnel reflection is 28.7%. Without considering other transmission losses, the transmission efficiency is 71.3%. Thus, it can be seen that introducing the infrared optical glue 3 can effectively reduce the Fresnel reflection of the end face, and the transmission efficiency of the optical fiber combiner at 1550 nm is increased by 20.2%. At the same time, experimental verification is carried out. The optical fiber bundle and the end cap are glued in the air and the infrared optical glue 3 respectively. At the same wavelength, the transmission efficiency of the optical fiber combination also increases by about 20%.

[0030] 2. Regarding the efficiency improvement of the beam combiner by introducing optical glue Fiber optic bundle + GeAsS: The preparation method is the same as that of the high-power glued fiber optic beam combiner in Specific Example 2, except that the infrared optical glue 3 is omitted, and the fiber optic bundle and the end cap are glued in air, the same as the above control group.

[0031] Fiber optic bundle + optical glue + GeAsS: The high-power glued fiber optic beam combiner prepared by the method of Specific Example 2.

[0032] Fiber optic bundle + optical glue + GeAsS + optical glue + CaF 2 : Evenly apply the infrared optical glue 3 to the front end of the end cap of the high-power glued fiber optic beam combiner prepared by the method of Specific Example 2, and then add CaF 2 window pane.

[0033] The results are as Figure 5 shown. For the fiber optic bundle + GeAsS (red line), its transmission efficiency is 43.7% - 46.7%. For the fiber optic bundle + optical glue + GeAsS (blue line), its transmission efficiency is 64.1% - 69.7%. For the fiber optic bundle + optical glue + GeAsS (green line), its transmission efficiency is 70.6% - 74.7%. Thus, it can be seen that introducing the infrared optical glue 3 can effectively improve the transmission efficiency of the beam combiner.

[0034] 3. Regarding the test of the transmission efficiency and power threshold of the glued beam combiner Measurement method: First, build a 1550nm laser platform, test the output power of the laser, from 10mw to 100mw, take one data every 10mw for a total of 10 data. Use these 10 data as the input power of the beam combiner, place the prepared beam combiner on the built optical path platform, test the output power of each path of the beam combiner, and correspondingly take 10 data. The average value of the ratio of the output power to the input power is the transmission efficiency of each path of the beam combiner.

[0035] The results are as Figure 6 shown. The transmission efficiencies of each path of the laser of the tested fiber optic beam combiner under 1550nm laser are 73.2%, 68.7%, 69.6%, 67.5%, 68.3%, 69.8%, 68.1% respectively, and the transmission efficiency of path 1 is 73.2%.

[0036] Secondly, build a 4.7μm laser platform, and its test method is similar to the efficiency test method in Comparative Experiment 3. In this case, the 4.7μm laser is used for the power threshold part of the test, and only the power input and output under a single path are tested. The power test results of the 4th single path of the beam combiner are as Figure 7As shown, the maximum output power reaches 1.315 W, with an input power of 2.78 W at this time. When the input power increases to 3.31 W, the output power drops to 1.03 W. The glued part of the beam combiner was inspected under an infrared camera, and the highest temperature of the glued part was 73.2 °C, and the beam combiner did not get damaged.

[0037] 4. Regarding the stability test of the glued beam combiner Test method: The laser platform was set up in the same way as the 1550 nm laser experiment platform in Comparative Experiment 3, and the test method was the same. The complete fiber beam combination was stored in a drying cabinet, and then it was tested 2 - 3 times a day. So far, it has been tested more than 60 times.

[0038] The test results are as Figure 8 shown. When the fiber beam combiner is input with 1550 nm laser, the efficiency of each path fluctuates slightly, all between 66% - 75%. The inset shows the end face arrangement of the fiber bundle at the front end of the beam combiner and a physical picture of the complete beam combiner. The data in the figure are the efficiency stabilities of 7 channels of the beam combiner. Thus, it can be seen that during the test, the efficiency of the glued fiber beam combiner can be well stabilized between 66% - 75%.

[0039] The above description is not a limitation of the present invention, nor is the present invention limited to the above examples. Any changes, modifications, additions, or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention shall also fall within the protection scope of the present invention.

Claims

1. A high-power glued optical fiber combiner, characterized in that: It includes an untapered input optical fiber bundle, an output optical fiber end cap and infrared optical glue. The untapered input optical fiber bundle is inserted into a metal ferrule. The untapered input optical fiber bundle and the output optical fiber end cap are glued together by infrared optical glue. The infrared optical glue bonding part is encapsulated and fixed by a quartz glass tube.

2. A high-power glued optical fiber combiner according to claim 1, characterized in that: The infrared optical adhesive is composed of As, S, I and Se elements, wherein the atomic percentage range of As is 10 to 50 at%, the atomic percentage range of S is x; the atomic percentage range of Se is y, wherein x+y=10 to 68 at%, y>0; the atomic percentage range of I is 0 to 35 at%, and the refractive index range of the infrared optical adhesive is 2.11 to 2.

24.

3. The high-power glued optical fiber combiner according to claim 1, characterized in that: The un-tapered input optical fiber bundle is composed of 7 As2S3 optical fibers with large mode field area arranged in a regular hexagon.

4. The high-power glued optical fiber combiner according to claim 1, characterized in that: The output optical fiber end cap is made by taper-drawing a GeAsS preform.

5. A method for preparing a high-power glued optical fiber combiner according to any one of claims 1 to 4, characterized in that The following steps are involved: Step 1, preparing an input fiber bundle for energy input of a high-power fiber laser; Step 2, preparing an output fiber end cap for energy output of a high-power fiber laser; Step 3: Bond the input fiber bundle and the output fiber end cap by infrared optical glue to obtain a high-power bonded fiber combiner that meets the requirements of high-power laser transmission in the mid-infrared band.

6. The method for preparing a high-power glued optical fiber combiner according to claim 5, characterized in that Step 1 is as follows: (1) Prepare 7 As2S3 optical fibers with large mode field areas and a metal ferrule with a diameter equal to the long side of the 7 optical fibers arranged in a regular hexagon; (2) Arrange 7 As2S3 optical fibers tightly and symmetrically in a cluster, insert them into the metal ferrule, evenly apply high-temperature curing glue between the arranged As2S3 optical fibers and the metal ferrule, fix the position of the As2S3 optical fibers in the ferrule, and place the assembled optical fiber bundle in an oven for curing; (3) Prepare the end face of the ground and polished solidified optical fiber bundle, and obtain an input optical fiber bundle with reduced surface scratches and a smooth end face through the processes of rough grinding, medium grinding, fine grinding, and polishing.

7. The method for preparing a high-power glued optical fiber combiner according to claim 5, characterized in that Step 2 is as follows: (1) Prepare a GeAsS large core preform and cut it to the required length. Control the heating temperature of the temperature zone of the drawing tower to form a cone at the front end of the large core preform. At the same time, make the inner core at the rear end of the large core preform into a shape that matches the outer diameter of the input optical fiber bundle to obtain a GeAsS end cap. (2) Grind the end of the GeAsS end cap glued to the input optical fiber bundle. During the grinding process, use gradually finer grinding sandpaper to grind the end surface, and finally obtain the output optical fiber end cap.

8. The method for preparing a high-power glued optical fiber combiner according to claim 5, characterized in that Step 3 is as follows: (1) Apply infrared optical glue with good transmittance in the infrared spectrum range evenly on the contact surface between the input fiber bundle and the output fiber end cap and completely cover it; (2) The bonding part between the input fiber bundle and the output fiber end cap is encapsulated with a quartz glass tube, and the gap between the quartz glass tube and the metal ferrule is filled with glue to obtain a high-power glued fiber combiner.

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