Tapered optical fiber corrosion device and method for manufacturing space division multiplexer / demultiplexer

Abstract

The invention discloses a tapered optical fiber corrosion device and method for manufacturing a space division multiplexer / demultiplexer, and belongs to the field of multi-core optical fiber communication. The device comprises an optical fiber clamp, an adjusting frame, a partition plate, a polytetrafluoroethylene test tube, a polytetrafluoroethylene guide tube, a tripod, a test tube sealing cover and an injector, and the whole device is arranged in a fuming cupboard. The method comprises the following steps that a part of a coating layer at one end of each optical fiber of an optical fiber bundle is peeled off and wiped clean, and each optical fiber penetrates through a thin hole of a partition plate and is aligned after penetrating through the partition plate; the optical fiber with the exposed cladding is placed in a hydrofluoric acid solution to be corroded, then the solution is pumped out at a constant speed till all the optical fiber is pumped out, and the processed optical fiber bundle is moved into deionized water to be soaked and cleaned and is blow-dried to obtain the needed optical fiber bundle. According to the method, the preparation efficiency and the yield are improved, and the prepared space division multiplexing / demultiplexing device is high in precision, good in optical fiber end face structure, low in insertion loss and capable of meeting the requirements of an optical fiber communication system.

Description

Technical Field

[0001] The invention belongs to the field of multi-core optical fiber communication, and in particular relates to a tapered optical fiber etching device and method for manufacturing a space division multiplexer / demultiplexer. Background Art

[0002] With the rapid growth of optical communication networks, the capacity of traditional single-mode fiber systems has reached its limit. The transmission capacity increases 10 times every 5 years. Data transmission places higher demands on optical communication networks, and there is an urgent need to increase the capacity of optical transmission media. The space division multiplexing technology of multi-core optical fiber utilizes the spatial dimension to ensure that the optical fiber transmission system has a large capacity, high efficiency and high performance. However, with the development of communication technology, the Internet has put forward higher requirements on the transmission capacity of optical fiber communication systems. Even with the support of time division multiplexing, wavelength division multiplexing and polarization state multiplexing technologies, traditional single-mode optical fiber (SMF) has inevitably reached the capacity bottleneck. Multi-core optical fiber space division multiplexing (SDM) technology has become one of the methods to solve the bottleneck of communication transmission capacity in the future. In order to achieve efficient interconnection and stable transmission between multi-core optical fiber communication systems and existing single-mode optical fiber systems, the preparation of fan-in and fan-out devices has become a key link in the practical application of SDM technology.

[0003] At present, the preparation technologies of multi-core fiber space division multiplexing / demultiplexing devices mainly include polymer waveguide method, free space optics method, cluster taper method and chemical etching method. Among them, the chemical etching method is a method of corroding the fiber bundle by chemical solvent to reduce the cladding diameter, and then inserting the corroded fiber bundle into the ceramic ferrule to physically dock with the multi-core fiber. Because of its simple preparation method, the prepared space division multiplexing / demultiplexer has high precision, small size and low cost, which has attracted the attention of researchers. However, the chemical etching method requires precise control of the concentration, temperature, time and other parameters of the corrosive agent to ensure that the fiber end face achieves the expected corrosion effect, which increases the complexity, difficulty and repeatability of the preparation process. Micron-level measurements are also easily affected by measurement errors. These problems all lead to poor end face structure of the prepared fan-in and fan-out devices, too high insertion loss of the prepared space division multiplexing / demultiplexer, and low efficiency and yield of the prepared space division multiplexing / demultiplexer that meets communication requirements. Summary of the invention

[0004] In order to overcome the problem that the existing chemical etching technology is difficult to achieve the required high-precision optical fiber size requirements in the process of preparing space-division multiplexers / demultiplexers, and to avoid the measurement error of the micron-level corroded optical fiber bundle, the present invention provides a novel tapered optical fiber etching device and method for making space-division multiplexers / demultiplexers. This method can be used to corrode the optical fiber bundle into a transitionally uniform cone, and the corroded cone section contains the required optical fiber size. The preparation process does not require the measurement of the size of the corroded optical fiber, and it can be directly inserted into the ceramic ferrule of the required size. This method improves the preparation efficiency and yield rate, and the prepared space-division multiplexer / demultiplexer has high precision, good optical fiber end face structure, and low insertion loss, which can meet the requirements of optical fiber communication systems.

[0005] A tapered optical fiber etching device for making a space division multiplexer / demultiplexer comprises an optical fiber clamp, an adjustment frame, a partition plate, a first polytetrafluoroethylene test tube, a first polytetrafluoroethylene conduit, a tripod, a test tube sealing cover, a syringe, a second polytetrafluoroethylene test tube and a second polytetrafluoroethylene conduit, wherein the tapered optical fiber etching device is placed in a fume hood;

[0006] An optical fiber clamp is arranged on the adjustment frame, an optical fiber bundle to be corroded is fixed on the optical fiber clamp, a first polytetrafluoroethylene test tube and a tripod are arranged below the optical fiber clamp, a partition plate is arranged between the optical fiber clamp and the first polytetrafluoroethylene test tube, the first polytetrafluoroethylene test tube is placed on the tripod, a second polytetrafluoroethylene test tube is arranged on one side of the tripod, and a test tube sealing cover is arranged on the upper part of the second polytetrafluoroethylene test tube.

[0007] The test tube sealing cover is provided with two circular holes, and the diameters of the circular holes are the same as the diameters of the first polytetrafluoroethylene conduit and the second polytetrafluoroethylene conduit.

[0008] One end of the first polytetrafluoroethylene conduit extends into the bottom of the first polytetrafluoroethylene test tube, the first polytetrafluoroethylene test tube contains a hydrofluoric acid solution, and the other end extends into the second polytetrafluoroethylene test tube through a round hole on the test tube sealing cover, with an extension length of 1 to 2 cm;

[0009] One end of the second polytetrafluoroethylene catheter extends into the second polytetrafluoroethylene test tube through another round hole on the test tube sealing cover, and the extension length is 1 to 2 cm; the other end of the second polytetrafluoroethylene catheter is connected to a syringe, and the outer diameter of the syringe needle is the same as the diameter of the second polytetrafluoroethylene catheter.

[0010] The two circular holes on the test tube sealing cover are sealed and fixed to the connection between the first polytetrafluoroethylene test tube and the second polytetrafluoroethylene test tube.

[0011] The partition plate is made of polytetrafluoroethylene, with a diameter of 5 to 8 cm and a thickness of 1 to 3 mm. There are 20 to 30 circular holes on the partition plate, and a single optical fiber in the optical fiber bundle passes through each hole. The diameter of the hole is 250 to 260 μm, and the distance between the centers of the holes is 2 to 5 mm.

[0012] A tapered optical fiber etching method for making a space division multiplexer / demultiplexer is implemented using the above device and specifically comprises the following steps:

[0013] 1) Strip 3 to 4 cm of the coating layer at one end of each optical fiber of the optical fiber bundle to be corroded, and wipe it clean with dust-free paper to obtain an optical fiber bundle with partially exposed cladding;

[0014] 2) passing each optical fiber of the optical fiber bundle obtained in step 1) through the fine hole of the partition plate, respectively, and ensuring that each optical fiber is aligned after passing through the partition plate;

[0015] 3) placing the exposed cladding portion of the optical fiber bundle in a hydrofluoric acid solution for corrosion;

[0016] 4) Extract the hydrofluoric acid solution at a constant speed of 5 to 8 mL / min until all the solution is extracted to obtain an optical fiber bundle with a corroded optical fiber segment;

[0017] 5) The optical fiber bundle treated in step 4) is moved to deionized water for soaking and cleaning for 3 to 5 minutes, and then the optical fiber bundle is blown dry to obtain an optical fiber bundle with a tapered corroded optical fiber segment.

[0018] in:

[0019] In the step 3), the mass concentration of the hydrofluoric acid solution is 35% to 45%, the corrosion temperature is 24 to 26° C., and the corrosion time is 20 to 25 minutes.

[0020] In the step 3), during the process of the hydrofluoric acid solution corroding the optical fiber bundle, the liquid level height remains unchanged.

[0021] In step 4), during the process of uniformly extracting the hydrofluoric acid solution, the liquid level decreases uniformly over time, the immersion time of the corroded optical fiber segment in the hydrofluoric acid solution gradually increases from top to bottom, and the size of the optical fiber gradually decreases from top to bottom.

[0022] In the step 4), the lower diameter of the corroded optical fiber segment is smaller than the upper diameter thereof; wherein the lower diameter of the corroded optical fiber segment is 35-38 μm, and the upper diameter is 44-48 μm.

[0023] In the step 5), the obtained tapered etched optical fiber segment includes the commonly used etched optical fiber size for preparing space division multiplexer / demultiplexer by chemical etching method, and the obtained optical fiber is inserted into a ceramic head of the required size to carry out subsequent preparation steps.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The method of the present invention uses a partition plate to separate the optical fibers before the corrosion treatment, so that each optical fiber can fully contact the hydrofluoric acid solution, thereby overcoming the problem of uneven optical fiber corrosion caused by the adhesion of the optical fibers in the optical fiber bundle during corrosion.

[0026] 2) The optical fiber etching method provided by the present invention etches the optical fiber into a cone shape through two-stage etching, so that the size of the obtained optical fiber is within a certain range, thereby continuing to prepare the multi-core optical fiber space division multiplexer without measuring the optical fiber after etching, thereby improving the efficiency and accuracy of the preparation of the multi-core optical fiber space division multiplexer.

[0027] 3) The conical optical fiber obtained by the optical fiber etching method provided by the present invention can obtain a uniform fiber core arrangement when inserted into a ceramic ferrule or an outer sleeve in the preparation of a multiplexer due to its high precision and uniformity, thereby reducing the insertion loss of the multi-core optical fiber space division multiplexer caused by uneven arrangement.

[0028] 4) The tapered optical fiber etching method provided by the present invention can realize the preparation of multiple products by one method by adjusting the process and process parameters. The preparation method is simple and effective, has a high success rate, has a high degree of matching with the multi-core optical fiber, and reduces the loss of the docking. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of a device for corroding a tapered optical fiber used for making a space division multiplexer / demultiplexer according to the present invention; wherein, 1-optical fiber bundle to be corroded, 2-optical fiber clamp, 3-adjusting frame, 4-fume hood, 5-partition plate, 6-hydrofluoric acid solution, 7-first polytetrafluoroethylene test tube, 8-first polytetrafluoroethylene conduit, 9-tripod, 10-test tube sealing cover, 11-syringe, 12-second polytetrafluoroethylene conduit, 13-second polytetrafluoroethylene test tube;

[0030] Figure 2 Schematic diagram of a partition plate for separating optical fibers according to the present invention; wherein Figure a is a diagram of a partition plate, and Figure b is a diagram of a partition plate passing through an optical fiber;

[0031] Figure 3 Fiber corrosion effect diagram in Example 1 of the present invention;

[0032] Figure 4 Schematic diagram of the end face of the four-core space division multiplexer in Example 1 of the present invention;

[0033] Figure 5 Schematic diagram of the packaging of a four-core space division multiplexer in Example 1 of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and implementation cases.

[0035] In the embodiment of the present invention, the adhesive used is 353ND glue, including two bottles of A and B, which are used in a ratio of 10:1, and the curing conditions are 100-120° C. and heating for 25-35 minutes.

[0036] In the embodiment of the present invention, the multi-core optical fiber used is a homogeneous multi-core optical fiber or a heterogeneous multi-core optical fiber.

[0037] Example 1

[0038] A tapered optical fiber etching device for making a space division multiplexer / demultiplexer, such as Figure 1 As shown, it includes an optical fiber clamp 2, an adjustment frame 3, a partition plate 5, a first polytetrafluoroethylene test tube 7, a first polytetrafluoroethylene conduit 8, a tripod 9, a test tube sealing cover 10, a syringe 11, a second polytetrafluoroethylene test tube 12 and a second polytetrafluoroethylene conduit 13, and the tapered optical fiber corrosion device is placed in a fume hood 4;

[0039] The optical fiber clamp 2 is arranged on the adjustment frame 3, and the optical fiber bundle 1 to be corroded is fixed on the optical fiber clamp 2. A first polytetrafluoroethylene test tube 7 and a tripod 9 are arranged below the optical fiber clamp 2. A partition plate 5 is arranged between the optical fiber clamp 2 and the first polytetrafluoroethylene test tube 7. The first polytetrafluoroethylene test tube 7 is placed on the tripod 9. A second polytetrafluoroethylene test tube 13 is arranged on one side of the tripod 9. A test tube sealing cover 10 is arranged on the upper part of the second polytetrafluoroethylene test tube 13.

[0040] The test tube sealing cover 10 is provided with two circular holes, and the diameters of the circular holes are the same as the diameters of the first polytetrafluoroethylene conduit 8 and the second polytetrafluoroethylene conduit 12 .

[0041] The first polytetrafluoroethylene conduit 8 has a size of 1.0×1.2×400 mm, one end of which extends into the bottom of the first polytetrafluoroethylene test tube 7, in which the hydrofluoric acid solution 6 is contained, and the other end of which extends into the second polytetrafluoroethylene test tube 13 through a circular hole on the test tube sealing cover 10, with an extension length of 2 cm;

[0042] The size of the second polytetrafluoroethylene catheter 12 is 1.0×1.2×80 mm, and one end thereof extends into the second polytetrafluoroethylene test tube 13 through another circular hole on the test tube sealing cover 10, with an extension length of 2 cm; the other end of the second polytetrafluoroethylene catheter 12 is connected to the syringe 11, and the outer diameter of the needle of the syringe 11 is 1 mm, which is the same as the diameter of the second polytetrafluoroethylene catheter 12.

[0043] The two circular holes on the test tube sealing cover 10 are sealed and fixed to the connection between the first polytetrafluoroethylene test tube 7 and the second polytetrafluoroethylene test tube 13 .

[0044] The schematic diagram of the partition plate 5 is as follows Figure 2 As shown, it is made of polytetrafluoroethylene, with a diameter of 5 cm and a thickness of 1 mm. There are 25 circular holes on the partition plate, and a single optical fiber in the optical fiber bundle passes through each hole. The diameter of the hole is 260 μm, and the distance between the centers of the holes is 5 mm.

[0045] Example 2

[0046] A tapered optical fiber etching method for making a space division multiplexer / demultiplexer, using Figure 1 The device implementation in the embodiment of the present invention takes a four-core space division multiplexer as an example, and specifically includes the following steps:

[0047] 1) Prepare a four-core optical fiber with a core spacing of d=41.5 μm; prepare four single-mode optical fibers with a cladding diameter α=125 μm and a core diameter r=9 μm, remove the organic coating layer at one end of the four single-mode optical fibers, and remove the organic coating layer for a length of 3 to 4 cm. After alignment, cut off the excess length to ensure that the lengths of the coating layer removal portions of the four optical fibers are equal, and wipe them clean with dust-free paper dipped in anhydrous ethanol to obtain a partially exposed cladding optical fiber bundle 1 to be corroded;

[0048] 2) passing each optical fiber of the optical fiber bundle obtained in step 1) through the fine hole of the partition plate 5, respectively, and ensuring that each optical fiber is aligned after passing through the partition plate;

[0049] Pass the four optical fibers to be corroded through any four holes of the partition plate, such as Figure 2 As shown, ensure that the coating removal portion of each optical fiber is aligned, use tape to stick the four optical fibers into a bundle at the tail of the end of the optical fiber where the coating is not removed, and use the optical fiber clamp 2 on the adjustment frame 3 to clamp the tail end of the optical fiber bundle so that it is suspended vertically.

[0050] 3) Place the first polytetrafluoroethylene test tube 7 on the tripod 9, and the second polytetrafluoroethylene test tube 13 on the table of the fume hood 4. Pour 24 mL of a 40% hydrofluoric acid solution into the first polytetrafluoroethylene test tube 7, and then immerse the portion of the optical fiber bundle from which the organic coating layer is removed into the hydrofluoric acid solution to corrode the cladding for 23 minutes. During the process of the hydrofluoric acid solution corroding the optical fiber bundle, the liquid level height remains unchanged, and the corrosion temperature is controlled at 25°C.

[0051] 4) Use the syringe 11 to extract 2 mL of air from the second polytetrafluoroethylene test tube 13. When the hydrofluoric acid solution 6 in the first polytetrafluoroethylene tube 8 begins to drip into the second polytetrafluoroethylene test tube 13, disconnect the syringe 11 from the second polytetrafluoroethylene tube 13. At this time, the hydrofluoric acid solution 6 in the first polytetrafluoroethylene test tube 7 continues to flow into the second polytetrafluoroethylene test tube 13 through the first polytetrafluoroethylene tube 1 at a rate of 5 mL / min until it is completely drained, and an optical fiber bundle with a corroded optical fiber segment is obtained. During the process of uniformly extracting the hydrofluoric acid solution, the liquid level decreases uniformly with time, the soaking time of the corroded optical fiber segment in the hydrofluoric acid solution gradually increases from top to bottom, and the optical fiber size gradually decreases from top to bottom, wherein the lower diameter of the corroded optical fiber segment is 35 μm, and the upper diameter is 46 μm.

[0052] 5) Take out the corroded fiber bundle and move it to deionized water to soak and clean for 5 minutes. Then use a hot air gun to blow dry the fiber to obtain a fiber bundle with a tapered corroded fiber segment. The fiber corrosion effect is as follows: Figure 3 As shown. The 4 treated corroded single-mode optical fibers are inserted into a ceramic head with an aperture of 100μm. The optical fibers are bonded to the ceramic head with a low-viscosity adhesive. The tail is reinforced by inserting a glass tube and a heat shrink tube filled with glue. After the whole is heated and cured, the front end of the ceramic head is ground and polished. Then, a physical contact docking method is used to dock with the four-core optical fiber to make a space division multiplexer for four-core optical fiber communication. The average insertion loss of the manufactured four-core space division multiplexer is 1.26dB. The front end surface of the four-core multiplexer docking is as shown. Figure 4 As shown, the four-core multiplexer product package is as follows Figure 5 The performance of the prepared four-core space division multiplexer is shown in Table 1.

[0053] Table 1 Performance of the four-core space division multiplexer prepared in Example 1

[0054]

[0055]

Claims

1. A tapered optical fiber etching device for making a space division multiplexer / demultiplexer, characterized in that: It includes an optical fiber clamp, an adjustment frame, a partition plate, a first polytetrafluoroethylene test tube, a first polytetrafluoroethylene conduit, a tripod, a test tube sealing cover, a syringe, a second polytetrafluoroethylene test tube and a second polytetrafluoroethylene conduit, wherein the tapered optical fiber corrosion device is placed in a fume hood; An optical fiber clamp is arranged on the adjustment frame, an optical fiber bundle to be corroded is fixed on the optical fiber clamp, a first polytetrafluoroethylene test tube and a tripod are arranged below the optical fiber clamp, a partition plate is arranged between the optical fiber clamp and the first polytetrafluoroethylene test tube, the first polytetrafluoroethylene test tube is placed on the tripod, a second polytetrafluoroethylene test tube is arranged on one side of the tripod, and a test tube sealing cover is arranged on the upper part of the second polytetrafluoroethylene test tube; The test tube sealing cover is provided with two circular holes, and the diameters of the circular holes are the same as the diameters of the first polytetrafluoroethylene conduit and the second polytetrafluoroethylene conduit.

2. The tapered optical fiber etching device for making a space division multiplexer / demultiplexer according to claim 1, characterized in that: One end of the first polytetrafluoroethylene conduit extends into the bottom of the first polytetrafluoroethylene test tube, the first polytetrafluoroethylene test tube contains a hydrofluoric acid solution, and the other end extends into the second polytetrafluoroethylene test tube through a round hole on the test tube sealing cover, with an extension length of 1 to 2 cm; One end of the second polytetrafluoroethylene catheter extends into the second polytetrafluoroethylene test tube through another round hole on the test tube sealing cover, and the extension length is 1 to 2 cm; the other end of the second polytetrafluoroethylene catheter is connected to a syringe, and the outer diameter of the syringe needle is the same as the diameter of the second polytetrafluoroethylene catheter.

3. The tapered optical fiber etching device for making a space division multiplexer / demultiplexer according to claim 1, characterized in that: The two circular holes on the test tube sealing cover are sealed and fixed to the connection between the first polytetrafluoroethylene test tube and the second polytetrafluoroethylene test tube.

4. The tapered optical fiber etching device for making a space division multiplexer / demultiplexer according to claim 1, characterized in that: The partition plate is made of polytetrafluoroethylene, with a diameter of 5 to 8 cm and a thickness of 1 to 3 mm. There are 20 to 30 circular holes on the partition plate, and a single optical fiber in the optical fiber bundle passes through each hole. The diameter of the hole is 250 to 260 μm, and the distance between the centers of the holes is 2 to 5 mm.

5. A tapered optical fiber etching method for making a space division multiplexer / demultiplexer, implemented by the device of claim 1, characterized in that: The specific steps include: 1) Strip 3 to 4 cm of the coating layer at one end of each optical fiber of the optical fiber bundle to be corroded, and wipe it clean with dust-free paper to obtain an optical fiber bundle with partially exposed cladding; 2) passing each optical fiber of the optical fiber bundle obtained in step 1) through the fine hole of the partition plate, respectively, and ensuring that each optical fiber is aligned after passing through the partition plate; 3) placing the exposed cladding portion of the optical fiber bundle in a hydrofluoric acid solution for corrosion; 4) Extract the hydrofluoric acid solution at a constant speed of 5 to 8 mL / min until all the solution is extracted to obtain an optical fiber bundle with a corroded optical fiber segment; 5) The optical fiber bundle treated in step 4) is moved to deionized water for soaking and cleaning for 3 to 5 minutes, and then the optical fiber bundle is blown dry to obtain an optical fiber bundle with a tapered corroded optical fiber segment.

6. A tapered optical fiber etching method for making a space division multiplexer / demultiplexer according to claim 5, characterized in that: In the step 3), the mass concentration of the hydrofluoric acid solution is 35% to 45%, the corrosion temperature is 24 to 26° C., and the corrosion time is 20 to 25 minutes.

7. The tapered optical fiber etching method for manufacturing a space division multiplexer / demultiplexer according to claim 5, characterized in that: In the step 3), during the process of the hydrofluoric acid solution corroding the optical fiber bundle, the liquid level height remains unchanged.

8. The tapered optical fiber etching method for making a space division multiplexer / demultiplexer according to claim 5, characterized in that: In step 4), during the process of uniformly extracting the hydrofluoric acid solution, the liquid level decreases uniformly over time, the immersion time of the corroded optical fiber segment in the hydrofluoric acid solution gradually increases from top to bottom, and the size of the optical fiber gradually decreases from top to bottom.

9. The tapered optical fiber etching method for manufacturing a space division multiplexer / demultiplexer according to claim 5, characterized in that: In the step 4), the lower diameter of the corroded optical fiber segment is smaller than the upper diameter thereof; wherein the lower diameter of the corroded optical fiber segment is 35-38 μm, and the upper diameter is 44-48 μm.

10. The tapered optical fiber etching method for manufacturing a space division multiplexer / demultiplexer according to claim 5, characterized in that: In the step 5), the obtained tapered etched optical fiber segment includes the commonly used etched optical fiber size for preparing space division multiplexer / demultiplexer by chemical etching. The obtained optical fiber is inserted into a ceramic head of the required size to carry out subsequent preparation steps.

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