Manufacturing method of beam combiner

Abstract

The invention belongs to the technical field of beam combiner manufacturing, and discloses a beam combiner manufacturing method, which comprises the following steps: carrying out primary dispensing on a non-coating layer on one side of a multi-fiber stripping opening of an optical fiber bundle by using low-refractive-index glue so as to fix the relative positions of a pumping optical fiber and a signal optical fiber; the optical fiber bundle is placed in the packaging container in a suspended state, secondary dispensing is carried out at the multi-fiber stripping opening of the optical fiber bundle by using the low refractive index again so as to keep the suspended state, and the range of secondary dispensing covers a part of the coating layer and the primary dispensing position; and dispensing the multi-fiber coating layer and the single-fiber coating layer of the optical fiber bundle by using high-refractive-index glue. According to the invention, by weighing the heat dissipation and fixing functions of the glue and the influence of the acting force on the optical fiber bundle, the packaging is better realized, so that the long-term reliable use of the beam combiner is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of beam combiner manufacturing, and in particular relates to a method for manufacturing a beam combiner. Background Art

[0002] The failure or damage of the combiner manifests itself as reduced efficiency, heat generation and burning. The main reasons for these problems are changes in fiber parameters, deformation and breakage, and these changes mainly depend on the influence of the fiber bundle packaging materials and methods inside the combiner. Because the performance of the optical fiber itself is relatively excellent and stable, but after long-term use (usually more than one year), the material properties of the optical fiber change significantly, so the risk of using the combiner is significantly increased.

[0003] The encapsulation of the fiber bundle within the combiner involves glue. Glue materials are divided into glue that can be used for the fiber cladding (a low-refractive-index glue with a lower refractive index than the fiber cladding) and glue that can be used for the fiber coating (a high-refractive-index glue with a higher refractive index than the fiber cladding). Because the glue directly contacts and covers the fiber bundle, its changing forces (stretching and shrinking) will also directly act on the fiber bundle, affecting its deformation and breakage. Especially under changes in temperature and humidity parameters, the glue will undergo significant expansion or contraction, which will increase the force exerted by the encapsulation on the fiber bundle, affecting the reliability of the combiner's fiber bundle.

[0004] Furthermore, if the properties of the low-refractive-index glue covering the optical fiber cladding change, its refractive index will no longer be lower than that of the optical fiber cladding, making it more susceptible to light absorption and heat generation, leading to burns. Therefore, the larger the contact area between the glue material and the optical fiber bundle (the greater the amount used), the more stable the optical fiber bundle. However, if the properties of the glue material change, the larger the contact area between the glue and the optical fiber bundle, the greater the risk variable. Therefore, it is necessary to make trade-offs in the location and amount of glue used to achieve the most stable and effective packaging. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention discloses a method for manufacturing a combiner, which balances the heat dissipation and fixing functions of the glue and the influence of the force on the optical fiber bundle to better achieve packaging, thereby realizing long-term and reliable use of the combiner.

[0006] The specific technical solutions of the present invention are as follows:

[0007] A method for manufacturing a beam combiner, comprising:

[0008] S101, obtaining two pump optical fibers, stripping and cleaning the coating of a first preset length of the pump optical fibers, then tapering the pump optical fibers to a process length and process diameter, and truncating the pump optical fibers at the minimum process diameter;

[0009] S102, obtaining a signal optical fiber, stripping a second preset length of the coating layer in the middle section of the signal optical fiber and cleaning it;

[0010] S200, fixing both ends of the signal fiber, placing a pump fiber on both sides of the same end of the signal fiber, and leaving the cut ends of the two pump fibers suspended in the air and intersecting at the middle of the signal fiber;

[0011] S300, adhering the heat pump fiber to the signal fiber, heating the bonding area of the pump fiber and the signal fiber using a heat source, fusing the pump fiber and the signal fiber to form a fiber bundle, maintaining the heating temperature, and tapering the fiber bundle to a preset shape to complete the firing;

[0012] Use low-refractive-index glue to apply glue once to the non-coating layer on the multi-fiber stripping side of the fiber bundle to fix the relative positions of the pump fiber and the signal fiber;

[0013] Place the optical fiber bundle in a suspended state into the packaging container, and use a low-refractive-index glue to dispense a second time at the multi-fiber stripping end of the optical fiber bundle to keep it suspended. The second glue dispensing covers a part of the coating layer and the first glue dispensing area.

[0014] Dispense the multi-fiber coating and single-fiber coating of the optical fiber bundle with high refractive index glue;

[0015] Encapsulate fiber bundles.

[0016] Preferably, the packaging container comprises a metal base and a quartz tank, the metal base has a placement groove, and the quartz tank is bonded into the placement groove;

[0017] The optical fiber bundle spans the placement groove and is fixed to the metal seat. The portion of the optical fiber bundle spanning the placement groove is located in the quartz groove. Secondary glue is dispensed in the quartz groove to allow the optical fiber bundle to be suspended in the quartz groove.

[0018] Preferably, the optical fiber bundle is located at the center of the quartz tank.

[0019] Preferably, a clean cotton swab is dipped in a highly volatile liquid and repeatedly touched to the pump fiber along the direction from thick to thin in the tapered region of the pump fiber, so that the pump fiber adheres to the signal fiber.

[0020] Preferably, both ends of the signal optical fiber are fixed on a first fixture and a second fixture of a taper drawing machine, respectively, and the pump optical fiber is fixed on the first fixture;

[0021] During the process of drawing the tapered optical fiber bundle into a preset shape, the first clamp is stationary, and the second clamp moves in a direction away from the first clamp under preset conditions.

[0022] Preferably, high refractive index glue is injected at the multi-fiber input end point of the optical fiber bundle, and there is a distance between this point and the position of the secondary glue injection;

[0023] Inject at least two sections of high refractive index glue with intervals at the single fiber output end of the optical fiber bundle.

[0024] Preferably, the total length of the high-refractive-index glue and the low-refractive-index glue dispensed is less than 25% of the length of the quartz tank.

[0025] Preferably, the length of each section of glue injection is 5mm to 10mm.

[0026] Preferably, there is a distance between the position of the primary dispensing and the multi-fiber stripping end of the optical fiber bundle.

[0027] Preferably, there is a distance between the high refractive index glue injected at the single fiber output end of the optical fiber bundle and the single fiber stripping end of the optical fiber bundle.

[0028] Compared with the existing technology, the present invention melts the tail end of the pump fiber into the signal fiber, so that the optical energy at the tail end of the pump fiber is directly injected into the signal fiber that can better withstand heat, rather than being scattered into the adjacent single fiber stripping and coating layer, thereby ensuring the long-term reliability of the combiner; in addition, the present invention rationally configures the glue injection position and reasonably distributes the glue usage to reduce risk variables, thereby improving the reliability of the combiner. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of a cutaway portion of a pump fiber according to an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of the intersection of the pump fiber and the signal fiber in an embodiment of the present invention;

[0031] Figure 3 Schematic diagram of the process of laminating a pump fiber to a signal fiber in an embodiment of the present invention;

[0032] Figure 4 In the embodiment of the present invention Figure 3 Schematic diagram of the fitting result;

[0033] Figure 5 Schematic diagram of the area scanned by the heat source in an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the results of firing and melting in this embodiment;

[0035] Figure 7 A schematic diagram of placing an optical fiber bundle into a packaging container according to an embodiment of the present invention;

[0036] Figure 8 Schematic diagram of the position for dotting low-refractive-index glue in an embodiment of the present invention;

[0037] Figure 9Schematic diagram of the position for dotting high refractive index glue in an embodiment of the present invention;

[0038] Figure 10 It is a schematic diagram of burning in the prior art;

[0039] Figure 11 Schematic diagram of the experimental temperature measurement position in an embodiment of the present invention.

[0040] In the figure: 1-metal base; 2-magnet; 3-fiber bundle; 4-quartz groove; 5-low refractive index glue; 6-high refractive index glue; 7-single fiber stripping end; 8-first clamp; 9-second clamp; 10-cotton swab; 100-pump fiber; 200-signal fiber. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0042] To address the problem of side-pumped 2+1 combiners often burning out after a certain period of use (not less than one year), this embodiment discloses a method for manufacturing the combiner, including:

[0043] S100, obtaining two pump optical fibers 100, stripping and cleaning the coating of a first preset length of the pump optical fibers 100, then tapering the pump optical fibers 100 to a process length and process diameter, and truncating the pump optical fibers 100 at the minimum process diameter;

[0044] S200, obtaining a signal optical fiber 200, stripping and cleaning the coating of a second preset length of the middle section of the signal optical fiber 200;

[0045] S300, fixing both ends of the signal optical fiber 200, placing a pump optical fiber 100 on both sides of the same end of the signal optical fiber 200, and leaving the cut ends of the two pump optical fibers 100 suspended in the air and intersecting at the middle section of the signal optical fiber 200;

[0046] S400, adhering the heat pump fiber 100 to the signal fiber 200, heating the bonding area of the pump fiber 100 and the signal fiber 200 using a heat source, so that the pump fiber 100 and the signal fiber 200 fuse to form a fiber bundle 3, maintaining the heating temperature, and tapering the fiber bundle 3 to a preset shape to complete the firing;

[0047] S500, using low-refractive-index glue 5 to dispense glue once on the non-coating layer on one side of the multi-fiber stripping end of the optical fiber bundle 3 to fix the relative positions of the pump optical fiber 100 and the signal optical fiber 200;

[0048] S600, placing the optical fiber bundle 3 in a suspended state into the packaging container, and performing a second glue application using a low refractive index glue at the multi-fiber stripping end of the optical fiber bundle 3 to maintain the suspended state, with the second glue application covering a portion of the coating layer and the first glue application area;

[0049] S700, dispensing the multi-fiber coating layer and the single-fiber coating layer of the optical fiber bundle 3 with high-refractive-index glue 6;

[0050] S800, encapsulating optical fiber bundle 3.

[0051] In the above steps, the order of S100 and S200 can be changed, and these two steps can also be performed simultaneously. Figure 1 As shown, the pump fiber 100 is cut at the point where the process diameter is the smallest, that is, after tapering, the pump fiber 100 is cut at the thinnest point of the pump fiber 100. For the two pump fibers 100, it is best if the lengths after cutting are the same, and the coating portion of both is stripped to the part where the diameter is reduced by tapering. This allows the two pump fibers 100 to be well matched on both sides of the signal fiber 200, so that the signal fiber 200 is evenly stressed, thereby better meeting performance requirements. Figure 2 As shown, for the signal optical fiber 200, the coating layer that is stripped is the middle section, and its two ends are placed on the hydrogen-oxygen taper drawing machine, one end is located on the first clamp 8, and the other end is located on the second clamp 9, that is, the two ends of the signal optical fiber 200 are respectively fixed on the first clamp 8 and the second clamp 9 of the taper drawing machine; at the same time, the pump optical fiber 100 is fixed on the first clamp 8, so that after the pump optical fiber 100 and the signal optical fiber 200 form the optical fiber bundle 3, the optical fiber bundle 3 can be better fixed.

[0052] The first fixture 8 and the second fixture 9 each have a first positioning slot, a second positioning slot, and a third positioning slot. The first positioning slot is located between the second and third positioning slots. The first positioning slot is used to accommodate the signal fiber 200, while the second and third positioning slots are each used to accommodate a pump fiber 100. The two pump fibers 100 are symmetrical with respect to the signal fiber 200. Thus, after being positioned, the signal fiber 200 and the pump fiber 100 can naturally intersect, with the intersection located midway between the stripped coatings of the signal fiber 200. The signal fiber 200 and the pump fiber 100 are secured by a magnet 2, which is simple and easy to operate.

[0053] like Figure 3 As shown, in this embodiment, a highly volatile liquid is used to make the pump fiber 100 adhere to the signal fiber 200. Specifically, a clean cotton swab 10 is dipped in the highly volatile liquid and repeatedly touched with the pump fiber 100 along the direction from thick to thin in the tapered region of the pump fiber 100, so that the pump fiber 100 adheres to the signal fiber 200. The highly volatile liquid can be acetone, alcohol, etc. Thus, as Figure 4 As shown, the ultra-thin pump fiber 100, which was originally staggered with the signal fiber 200, will be adsorbed on both sides of the signal fiber 200 due to the tension of the liquid, and will still remain in contact with the signal fiber 200 after the liquid evaporates. Figure 5 and Figure 6 As shown, while the two pump fibers 100 and the signal fiber 200 are bonded together, the bonding area is burned using an oxyhydrogen flame as a heat source, completely fusing the two pump fibers 100 and the signal fiber 200. The cut portion of the pump fiber 100 is then integrated into the signal fiber 200, thereby forming a well-formed fiber bundle 3. Thus, the tail end of the pump fiber 100 is fused into the signal fiber 200, allowing the optical energy at the tail end of the pump fiber 100 to be directly injected into the pure quartz fiber (signal fiber 200, approximately 1200°C), which is more heat-resistant, rather than being scattered into the stripped ends and coating layers of the adjacent single fibers (approximately 200°C), thereby ensuring the long-term reliability of the combiner.

[0054] After the fiber bundle 3 is formed, it is slightly tapered. As can be seen from the above, since the two ends of the signal optical fiber 200 are respectively fixed to the first clamp 8 and the second clamp 9, after the fiber bundle 3 is formed, it is equivalent to the two ends of the fiber bundle 3 being respectively fixed to the first clamp 8 and the second clamp 9. Therefore, the shape of the fiber bundle 3 can be adjusted by the tapering machine. Specifically, after the fiber bundle 3 is fused, the flame temperature is maintained. During the process of tapering the fiber bundle 3 to a preset shape, the first clamp 8 is stationary, and the second clamp 9 moves in a direction away from the first clamp 8 under preset conditions. In this embodiment, the preset conditions are:

[0055] The movement speed of the second clamp 9 is 0.01 mm / s;

[0056] The heat source scans the optical fiber bundle 3 at a speed of 0.5 m / s and a scanning length of 5 cm. The heat source scans from the coated end toward the cutoff of the pump optical fiber 100, with the scan ending 5 mm ahead of the cutoff.

[0057] The hydrogen flow rate of the heat source flame is controlled to be 130 sccm, and the oxygen flow rate is controlled to be 25 sccm.

[0058] In step S500, after the firing is completed, a low-refractive-index glue 5 is dispensed at a distance of 5 mm from the multi-fiber stripping end of the optical fiber bundle 3. The glue dispensing length is 2 mm, and the glue dispensing width is sufficient to cover the three optical fibers. Then, the glue is cured using an ultraviolet lamp to fix the relative positions of the three optical fibers and prevent the fusion point from being dispersed by force during the subsequent movement of the optical fiber bundle 3. Figure 5 As shown, in the above process, the low refractive index glue 5 should be outside the bonding area of the pump fiber 100, that is, outside the scanning area of the heat source. The reason is that the burned optical fiber is easy to break, and slight changes in the glue stress may cause damage to the optical fiber.

[0059] like Figure 7 As shown, in this embodiment, the packaging container includes a metal base 1 and a quartz tank 4. The metal base 1 has a placement groove, and the quartz tank 4 is bonded to the placement groove. The optical fiber bundle 3 spans the placement groove and is fixed to the metal base 1. The portion of the optical fiber bundle 3 spanning the placement groove is located in the quartz tank 4. A second glue is dispensed in the quartz tank 4 to suspend the optical fiber bundle 3 in the quartz tank 4. Similarly, the optical fiber bundle 3 is fixed to the metal base 1 via the magnet 2. Glue is injected into the placement groove of the metal base 1 so that the quartz tank 4 can be stably bonded to the placement groove. The optical fiber bundle 3 is placed in the quartz tank 4, and the metal base 1 is attracted by the magnet 2 to fix the optical fiber bundle 3 between the magnet 2 and the metal base 1. Furthermore, after completing the above steps, the optical fiber bundle 3 is located at the center of the quartz tank 4, thereby ensuring the use effect of the optical fiber bundle 3.

[0060] The second dispensing is completed in step S600. Specifically, Figure 8 As shown, low-refractive-index glue 5 is applied to a 10 mm area around the multi-fiber stripping end of the optical fiber bundle 3 within the quartz tank 4, covering the low-refractive-index glue 5 applied in the first application. This allows the optical fiber bundle 3 to be completely suspended and fixed within the trapezoidal quartz tank 4. It can be seen that the 10 mm area around the multi-fiber stripping end of the optical fiber bundle 3 covers the first application area and part of the coating layer.

[0061] In step S700, high refractive index glue 6 is injected to better fix the optical fiber bundle 3. Specifically, Figure 9 As shown, high-refractive-index glue 6 is injected at the multi-fiber input end of the optical fiber bundle 3, and there is a gap between this point and the position of the secondary glue dispensing; at least two sections of high-refractive-index glue 6 with intervals are injected at the single-fiber output end of the optical fiber bundle 3. Furthermore, high-refractive-index glue 6 is dispensed on the coating layer of the input ends of the three optical fibers, separated from the low-refractive-index glue 5 at the input ends of the three optical fibers, to fix the multi-fiber portion of the optical fiber bundle 3. Two sections of high-refractive-index glue 6 are dispensed on the single-fiber portion of the optical fiber bundle 3. Specifically, high-refractive-index glue 6 is dispensed on the coating layer of a single optical fiber of the optical fiber bundle 3. From the multi-fiber portion of the optical fiber bundle 3 toward the single-fiber portion, the two sections of high-refractive-index glue 6 are 2 to 3 mm and 4 cm away from the single-fiber stripping end 7, respectively, and the dispensing lengths are 10 mm and 5 mm, respectively, to fix the output single fiber and dissipate heat from the single-fiber coating layer. In this embodiment, the length of the first 10 mm is to ensure that the high refractive index glue 6 has sufficient heat dissipation capacity, and the last 5 mm is to better achieve effective fixation of the optical fiber bundle 3. The dot injection in two sections can greatly reduce the amount of glue used.

[0062] Therefore, in the manufacturing process of this embodiment, the pump fiber 100 is first tapered and then cut at the thinnest part. Then, a clean cotton swab 10 dipped in a volatile liquid is used to straighten the pump fiber 100 so that it fits tightly on both sides of the signal fiber 200. In other words, the tension of the liquid is used to well achieve the matching of the pump fiber 100 and the signal fiber 200. Then, after the bonding is completed, the three optical fibers are burned and melted, and the burned and melted area includes the cut part of the pump fiber 100, so that the cut part of the pump fiber 100 is completely melted into the signal fiber 200, forming a more complete optical fiber bundle 3. Then, after the optical fiber bundle 3 is melted and burned, the entire optical fiber bundle 3 is slightly tapered according to preset conditions, so that the micro-collapse of the optical fiber bundle 3 during the melting process can be corrected, thereby reducing the loss of the optical fiber bundle 3.

[0063] It is known that the quartz tank 4 is made of pure silica. When using it for packaging, only cleanliness and appropriate dimensions are required; no other parameter requirements exist. However, the strength of the quartz tank 4 is significantly affected by external forces, meaning that the glue inside can adversely affect the quartz tank 4 under temperature fluctuations. Therefore, the amount of glue used should be as small as possible. In this embodiment, the quartz tank 4 is 150 mm long. In this embodiment, the total length of the high-refractive index glue 6 and the low-refractive index glue 5 is less than 25% of the length of the quartz tank 4, meaning the total length of the high-refractive index glue 6 and the low-refractive index glue 5 is less than 37.5 mm. This balance between the glue's heat dissipation and fixation function and the force applied to the optical fiber bundle 3 and the quartz tank 4 achieves the most stable and effective packaging. Furthermore, in this embodiment, the length of each glue injection section is 5 mm to 10 mm. This avoids excessive glue application and the resulting high force on the optical fiber bundle 3, while also meeting specific fixation requirements.

[0064] It should be further explained that, in this embodiment, the high refractive index glue 6 at the end of the multi-fiber input end of the optical fiber bundle 3 and the high refractive index glue 6 at the single fiber stripping position play an integral role in fixing the optical fiber bundle 3, and both are glued 10mm. At the same time, the high refractive index glue 6 at the single fiber stripping position also has the ability to dissipate heat for the coating layer of each optical fiber; and the low refractive index glue 5 at the multi-fiber stripping end of the optical fiber bundle 3 can fix the relative positions between the three optical fibers, which covers the stripping ends of the three input optical fibers and is glued 10mm. The low refractive index glue is glued at this position because the light leakage at this position The leakage is weak and is less affected by changes in glue performance. It can be seen that after one glue dispensing, there is a gap between each stripping end of the multi-fiber part and the low-refractive index glue 5, that is, there is a gap between the position of the first glue dispensing and the multi-fiber stripping end of the optical fiber bundle 3. The materials of the cladding light of the optical fiber bundle 3 and the external interface are optical fiber coating, air, low-refractive index glue 5, and air, respectively. After the second glue dispensing, the materials of the cladding light of the optical fiber bundle 3 and the external interface are optical fiber coating, low-refractive index glue 5, and air, respectively. It can be seen that glue dispensing at this position can also simplify the light transmission situation at the stripping position. In this embodiment, no glue is applied to the single-fiber stripping end 7 of the optical fiber bundle 3, where the optical fiber bundle 3 primarily leaks light. Instead, high-refractive-index glue 6 is applied to the coating 2 mm to 3 mm after the stripping. This creates a gap between the high-refractive-index glue 6 applied at the single-fiber output end of the optical fiber bundle 3 and the single-fiber stripping end 7 of the optical fiber bundle 3. This is because the high-NA pump light generated by the pump fiber 100 after tapering transitions more evenly to the single-fiber stripping end 7 of the optical fiber bundle 3, preventing heat accumulation in the small area of the single-fiber stripping end 7. Therefore, a section of high-refractive-index glue 6 is applied directly to the coating 2 mm to 3 mm after the single-fiber stripping end 7. This gradually guides the high-NA pump light through the high-refractive-index glue 6, thereby achieving uniform heat dissipation for the single-fiber portion of the optical fiber bundle 3. To prevent the optical fiber bundle 3 from shaking outside the quartz tank 4 and causing stretching inside the quartz tank 4, high-refractive-index glue 6 is applied to the single-fiber output end of the optical fiber bundle 3, with a gap of 5 mm.

[0065] like Figure 10As shown, if low-refractive-index glue 5 is injected at the single-fiber stripping end 7 of the optical fiber bundle 3, the transparent low-refractive-index glue 5 will turn yellow after the corresponding formed combiner has been used for a long time (more than one year). That is to say, the performance of the low-refractive-index glue 5 is deteriorated at this time, and the edge of the low-refractive-index glue 5 is prone to burn. Although the probability is low, it is not accidental. Therefore, the packaging stripping end does not adopt the method of injecting low-refractive-index glue. The reason is that the coating of the optical fiber itself is a low-refractive index coating, and the low-refractive index glue 5 covering the bare optical fiber is equivalent to the new coating of the optical fiber, and the edge of the low-refractive index glue 5 is the new stripping edge. Since the refractive index of the low-refractive index glue 5 is greater than the refractive index of air, when light is transmitted along the optical fiber cladding (bare fiber) to the edge of the low-refractive index glue 5, part of the light transmitted in the optical fiber cladding will leak into the low-refractive index glue 5. Once the low-refractive index glue 5 deteriorates over time (the refractive index increases), more light will leak into the low-refractive index glue 5, causing the temperature of the low-refractive index glue 5 to rise, and eventually reach the ignition point of the low-refractive index glue 5 and burn. In addition, the optical fiber coating is made through a strict process when drawing the optical fiber, and has better tightness than the subsequent low-refractive index glue 5. Therefore, in this embodiment, a small amount of low-refractive index glue 5 should be used, and high-refractive index glue 6 should be used appropriately. Therefore, light is transmitted in the optical fiber cladding, and the performance requirements of the glue that directly interacts with the cladding are high. When the high-refractive index glue 6 is injected on the optical fiber coating, there is a layer of optical fiber's own coating between the high-refractive index glue 6 and the cladding. Therefore, the light in the optical fiber cladding will not directly leak into the high-refractive index glue 6, but the part of the light that leaks into the optical fiber coating will be guided out, thereby achieving heat dissipation of the coating.

[0066] Therefore, the combiner obtained by this embodiment can continuously withstand extreme temperature storage of 24h×22 days at -40°C and 24h×22 days at 85°C 85% HR (after long-term use of the simulated device). After the extreme storage, the quartz device of the combiner is not cracked, and the optical fiber bundle 3 has no obvious deformation such as bending and breaking. In terms of the optical performance of the combiner, the pump efficiency fluctuation is ≤3%, and there is no burning. Except for the single-fiber input end of the multi-fiber part of the optical fiber bundle 3, the temperature fluctuation of each item is <10°C, which has good reliability.

[0067] It should be noted that after the combiner is stored at an extreme temperature of 85°C / 85% HR, the output end of the single-fiber portion of its optical fiber bundle 3 experiences a significant temperature rise. It is also observed that the temperature rise increases with storage time. This is due to the degradation of the optical fiber itself by the ambient temperature, namely, the degradation of the optical fiber coating material or the subtle separation of the coating and cladding. In an experiment to verify the cause of this problem, the optical fiber itself was stored at an extreme temperature of 85°C / 85% HR before the combiner was fabricated. It was found that the corresponding parts of the combiner also experienced the same temperature rise, indicating that the temperature rise is caused by the environment's impact on the optical fiber itself, rather than the process used in this embodiment.

[0068] Temperature extreme storage testing was conducted according to GB-T2423.2-2008 Experiment B: High Temperature Test Method and GJB150.3-2009 Military Equipment Laboratory Environmental Test Method Part 3: High Temperature Test. Low temperature testing was also conducted according to GB-T2423.2-2008 Experiment A: Low Temperature Test Method and GJB150.3-2009 Military Equipment Laboratory Environmental Test Method Part 4: Low Temperature Test. Before storage, all temperatures were tested to confirm that they were normal, and then the fiber bundle 3 was fully encapsulated. Full encapsulation seals the interior of the fiber bundle 3, preventing it from being opened to monitor the internal temperature. The test results are shown in Tables 1 and 2.

[0069] Temperature comparison of the combiner before and after storage at high temperature and high humidity (85℃ 85% HR) for 22 days (fully encapsulated) Table 1

[0070]

[0071]

[0072] Temperature comparison of the combiner before and after storage at low temperature (-45℃) for 22 days (fully packaged) Table 2

[0073]

[0074] In Tables 1 and 2 above, Figure 11 As shown: the bundle refers to the fitting position of the pump fiber 100 and the signal fiber 200; the cut refers to the single-fiber cut 7 of the optical fiber bundle 3; the former refers to the high-refractive-index glue 6 at the left end of the single-fiber part of the optical fiber bundle 3, and the latter refers to the high-refractive-index glue 6 at the right end; the internal optical fiber refers to the single-fiber part of the optical fiber bundle 3, the part of the optical fiber bundle 3 located between the two high-refractive-index glues 6 after the single-fiber cut 7; the output fiber refers to the output end of the single-fiber part of the optical fiber bundle 3; the input fiber refers to the input end of the multi-fiber part of the optical fiber bundle 3.

[0075] It is important to note that after extreme temperature storage at high temperature and high humidity, the temperature of the combiner's output fiber rose significantly. This is because the ambient temperature has a more serious impact on the degradation of the fiber's coating material, not the process itself. In the experiment, after the fiber itself was stored at the same temperature and then the combiner was made, the same temperature rise was still observed, thus emphasizing that it is not a process issue. Secondly, the high temperature and high humidity storage samples were more than the low temperature storage samples because the effects of high temperature and humidity are more obvious, and the number of samples was increased to better illustrate the superiority of the process.

[0076] As shown in the two tables, the combiner manufactured using the process of this embodiment showed no burnout after extreme high-temperature and high-humidity storage, with efficiency fluctuations ≤3%. Except for a temperature rise of >20°C in the output fiber, all other temperature fluctuations were ≤5°C. Furthermore, the combiner manufactured using the process of this embodiment showed no burnout after extreme low-temperature storage, with temperature fluctuations ≤5°C and efficiency fluctuations ≤3%. This indicates that the combiner manufactured using the process of this embodiment has superior performance, high reliability, and is suitable for long-term use.

[0077] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. Persons skilled in the art will appreciate that improvements and modifications may be made without departing from the spirit and scope of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a beam combiner, characterized in that: include: Obtain two pump fibers, strip the coating of a first preset length of the pump fibers and clean them, then taper them to a process length and process diameter, and cut the pump fibers at the minimum process diameter; Obtain a signal optical fiber, strip off a second preset length of the coating layer in the middle section of the signal optical fiber, and clean it; Fix the two ends of the signal fiber, place a pump fiber on both sides of the same end of the signal fiber, and let the cut ends of the two pump fibers hang in the air and intersect in the middle of the signal fiber; The heat pump fiber is adhered to the signal fiber, and the bonding area of the pump fiber and the signal fiber is heated by a heat source. The pump fiber and the signal fiber are fused to form a fiber bundle. The heating temperature is maintained and the fiber bundle is tapered to a preset shape to complete the firing. Use low-refractive-index glue to apply glue once to the non-coating layer on the multi-fiber stripping side of the fiber bundle to fix the relative positions of the pump fiber and the signal fiber; Place the optical fiber bundle in a suspended state into the packaging container, and use a low-refractive-index glue to dispense a second time at the multi-fiber stripping end of the optical fiber bundle to keep it suspended. The second glue dispensing covers a part of the coating layer and the first glue dispensing area. Dispense the multi-fiber coating and single-fiber coating of the optical fiber bundle with high refractive index glue; Encapsulate fiber bundles.

2. The method for manufacturing a beam combiner according to claim 1, wherein: The packaging container includes a metal base and a quartz tank, wherein the metal base has a placement groove, and the quartz tank is bonded in the placement groove; The optical fiber bundle spans the placement groove and is fixed to the metal seat. The portion of the optical fiber bundle spanning the placement groove is located in the quartz groove. Secondary glue is dispensed in the quartz groove to allow the optical fiber bundle to be suspended in the quartz groove.

3. The method for manufacturing a beam combiner according to claim 2, wherein: The optical fiber bundle is located at the center of the quartz tank.

4. The method for manufacturing a beam combiner according to claim 1, wherein: Use a clean cotton swab dipped in a highly volatile liquid and repeatedly touch the pump fiber along the direction from thick to thin in the tapered area of the pump fiber to make the pump fiber adhere to the signal fiber.

5. The method for manufacturing a beam combiner according to claim 1, wherein: The two ends of the signal optical fiber are respectively fixed on the first fixture and the second fixture of the taper drawing machine, and the pump optical fiber is fixed on the first fixture; During the process of drawing the tapered optical fiber bundle into a preset shape, the first clamp is stationary, and the second clamp moves in a direction away from the first clamp under preset conditions.

6. The method for manufacturing a beam combiner according to claim 1, wherein: Inject high refractive index glue at the multi-fiber input end of the optical fiber bundle, with a distance between this point and the secondary glue dispensing position; Inject at least two sections of high refractive index glue with intervals at the single fiber output end of the optical fiber bundle.

7. The method for manufacturing a beam combiner according to claim 1, wherein: The total length of the high-refractive-index glue and the low-refractive-index glue dispensed is less than 25% of the length of the quartz tank.

8. The method for manufacturing a beam combiner according to claim 1, wherein: The length of each glue injection point is 5mm to 10mm.

9. The method for manufacturing a beam combiner according to claim 1, wherein: There is a distance between the position of one dispensing and the multi-fiber stripping end of the optical fiber bundle.

10. The method for manufacturing a beam combiner according to claim 1, wherein: There is a distance between the high refractive index glue injected at the single fiber output end of the optical fiber bundle and the single fiber stripping end of the optical fiber bundle.

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