A method for manufacturing an optical fiber optical fluid channel

Abstract

The present invention relates to a method for making an optical fiber optical fluid channel, and the steps are as follows: Step 1, using a selective filling method based on polystyrene microspheres and paraffin oil to make a port at one end of a fluid channel at one end of a microstructure optical fiber; Step 2, when one end of the microstructure optical fiber is ventilated, using ultraviolet curing glue to block the other end of the optical fiber except for the port corresponding to the fluid channel, so as to make the other end of the fluid channel. Based on the treatment of one end of the optical fiber with polystyrene microspheres and paraffin oil, the present invention uses paraffin oil to connect the optical fiber to the needle of a syringe, and while slowly injecting air into the optical fiber, immerses the other end of the optical fiber into ultraviolet curing glue with low viscosity. Afterwards, the end is irradiated with an ultraviolet lamp, so that the pores at the same position of the end and the other end can be opened and closed, and the remaining pores are closed, thereby completing the production of the fluid channel in the optical fiber.

Description

Technical Field

[0001] The invention belongs to the technical field of optofluidic microcavity laser production, and particularly relates to a method for manufacturing an optical fiber optofluidic channel. Background Art

[0002] Optofluidic microcavity laser is an emerging miniaturized laser that combines optofluidic technology with micro-resonant cavity. It has the advantages of compact structure, easy integration, and low energy consumption. It is often used in chip laboratories, optofluidic sensors, integrated optical systems and other fields. On this basis, researchers combined bioluminescent materials with optofluidic microcavity lasers and proposed optofluidic biolasers. They also developed a series of applications in the analysis of biological materials such as DNA, peptides, and cells, enriching the means of biochemical detection. With the maturity of microstructured optical fiber drawing technology, the quartz wall structure with diverse structures embedded in microstructured optical fibers can be used as high-quality microcavities to build optofluidic microcavity lasers. Unlike common annular microcavities such as capillary microcavities and micro-nano fiber knot microcavities, which have defects such as fragile structure, low quality factor, and the need for external fluid channels, the microcavity embedded in the microstructured optical fiber has the characteristics of high quality factor, firm structure, and integration of multiple microcavities and fluid channels. Therefore, it has become an excellent platform for building optofluidic microcavity lasers. Since some characteristics of the microcavity, such as quality factor, shape, surface roughness, etc., will affect the threshold characteristics of the laser, the quality of the optical fiber can also be evaluated by the characteristics of the laser, which can be used for optical fiber screening in the development process of fiber optic gyroscopes based on hollow-core microstructured optical fibers.

[0003] Microstructured optical fiber is an excellent platform for building optofluidic microcavity lasers. However, its porous structure also brings certain difficulties to the production of fluid channels. When using microstructured optical fiber to build optofluidic microcavity lasers, how to make the fluid flow into the optical fiber from a specific hole and how to ensure that the waste liquid does not enter other holes of the optical fiber and affect the operation of the laser after flowing out of the optical fiber are issues that need to be considered. Therefore, there is an urgent need for a convenient and reliable method for making optical fiber optofluidic channels.

[0004] The production of fluid channels mainly involves the production of fluid inlets and outlets, that is, only one or several specific air holes in the microstructured optical fiber are exposed to the air, while the other air holes are blocked, which is the selective filling technology. When blocking, all air holes on both ends of the optical fiber except the entrance and exit of the fluid channel should be blocked to prevent the fluid from flowing out of the channel and entering the remaining air holes, affecting the performance of the laser. Common selective filling methods include the following:

[0005] 1. Hollow capillary assisted method: This method first requires selecting a capillary with an inner diameter that matches the size of the area to be filled, and then fusing the capillary with the optical fiber so that the liquid can enter the optical fiber through the capillary. This method can fill holes in a certain area of ​​the core or cladding, but it cannot complete the filling of specified air holes.

[0006] 2. Flow rate difference method: using the different flow rates of fluid in air holes of different sizes, use UV curing glue or molten paraffin to block air holes of different sizes at different lengths, and then cut the optical fiber to expose a series of air holes of the same size to the air. However, it still cannot fill a specific hole.

[0007] 3. Fusion machine discharge collapse air hole method: This method requires placing the optical fiber in a fusion machine for discharge. By controlling the discharge intensity and discharge time, the cladding air holes can be collapsed and closed, and only the larger air holes in the core are opened. This method requires strict control of the fusion machine parameters, but can only be used to fill the air holes in the core of a specific optical fiber.

[0008] 4. Micro-nano processing method: Use femtosecond laser hole opening and other precision micro-processing technologies to pre-process the optical fiber and fill specific air holes. This method can fill specific holes, but the disadvantage is that the technology is too complicated and requires extremely precise control means.

[0009] In addition, there is a selective filling method based on polystyrene microspheres and paraffin oil. In this method, the polystyrene microspheres are first moved to the top of the optical fiber air hole at a specific position by micromanipulation, and the polystyrene microspheres are melted at high temperature to block the specific air hole. Then, the paraffin oil is sucked into the remaining open and closed pores by capillary action, and the suction length is greater than the blocking length of the melted microspheres. Finally, a section immersed in the wax oil is retained, and the effect of opening and closing the pores at a specific position and closing the remaining pores can be achieved at one end of the optical fiber. Although this method is simple and flexible to operate and the equipment is simple compared to the above four methods. However, in actual operation, it is found that after the method is used to open and close the pores at a specific position at one end and the remaining pores are closed, the method cannot be used to achieve the same effect at the other end of the optical fiber. Therefore, the production of the fluid channel cannot be completed using only this method. The reason is that the viscosity of the paraffin oil is high, and the capillary effect will be weakened after one end of the optical fiber is blocked, and the paraffin oil cannot be sucked into the small holes in the optical fiber. Summary of the invention

[0010] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for manufacturing an optical fiber optical fluid channel which is simple to operate, easy to implement and has low manufacturing cost.

[0011] The above-mentioned object of the present invention is achieved by the following technical solutions:

[0012] A method for manufacturing an optical fiber optical fluid channel, characterized in that it comprises the following steps:

[0013] Step 1: A port at one end of a fluid channel is made at one end of a microstructured optical fiber by using a selective filling method based on polystyrene microspheres and paraffin oil;

[0014] Step 2: When one end of the microstructured optical fiber is ventilated, the other end of the optical fiber is sealed with ultraviolet curing glue except for the port corresponding to the fluid channel to make the other end port of the fluid channel.

[0015] Further: Step 1 comprises:

[0016] 1.1 Select a microstructured optical fiber, pre-treat both ends of the optical fiber, and place the optical fiber vertically under a microscope for standby use;

[0017] 1.2. Use a tapered capillary probe to suck up the polystyrene microspheres sprinkled on the microscope stage, move them to the upper end surface of the microstructured light, and accurately place them on the selected fluid channel port;

[0018] 1.3. Heat the polystyrene microspheres with an electric soldering iron, and remove the soldering iron tip after the melted part of the microspheres flows into the air holes;

[0019] 1.3. After the molten polystyrene liquid cools down, immerse one end of the processed optical fiber in the heated and melted paraffin oil. Under the capillary effect, the paraffin oil is absorbed into the remaining unblocked air holes. The length of the liquid column of the absorbed paraffin oil needs to be greater than the length of the polystyrene column entering the air hole.

[0020] 1.4. After the paraffin oil solidifies, cut off a section of the end. The cut length needs to be less than the column length of the inhaled paraffin oil and greater than the length of the polyethylene column, so that one end of the selected fluid channel is exposed and the remaining micropores are blocked by paraffin.

[0021] Further: Step 2 includes:

[0022] 2.1. Insert one end of the optical fiber processed in step 1 into the syringe needle, and drop paraffin oil onto the needle tip to achieve a sealing effect, so that the optical fiber is sealed and connected to the syringe needle;

[0023] 2.2. While slowly injecting air into the fluid channel using a syringe, place the end of the optical fiber to be blocked deeply into the UV-curing glue with lower viscosity. Under the action of capillary effect, the glue is sucked into the air hole to be blocked at the end to be blocked;

[0024] 2.3. Take the optical fiber out of the UV curing glue, wipe off the excess glue on the surface of the optical fiber, and then take the optical fiber out of the needle;

[0025] 2.4. Use ultraviolet light to irradiate the optical fiber to solidify the colloid in the optical fiber hole, and then cut off a small section of the optical fiber at this end, so that all air holes except the fluid channel port are blocked by solidified ultraviolet curing glue.

[0026] The present invention has the advantages and positive effects:

[0027] 1. Based on treating one end of the optical fiber with polystyrene microspheres and paraffin oil, the present invention connects the optical fiber to the syringe needle with paraffin oil, slowly injects air into the optical fiber, and immerses the other end of the optical fiber into a low-viscosity ultraviolet curing glue. After that, the end is irradiated with an ultraviolet lamp, so that the pores at the same position of the end and the other end can be opened and closed while the other pores are closed, thereby completing the production of the fluid channel in the optical fiber.

[0028] 2. The manufacturing method of the present invention can achieve the filling of designated air holes by using conventional operating equipment and conventional operating means. Compared with the existing process methods, the whole process is simple, easy to implement, and has a low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the present invention using a capillary probe to adsorb polystyrene microspheres;

[0030] Figure 2 is a schematic diagram of the present invention using a capillary probe to suck up polystyrene microspheres;

[0031] Figure 3 is a schematic diagram of using a capillary probe to move a polystyrene microsphere to a selected fluid channel port position in the present invention;

[0032] Figure 4 is a schematic diagram of the capillary probe of the present invention after being separated from the polystyrene microsphere;

[0033] Figure 5 is a schematic diagram of melting polystyrene microspheres with an electric soldering iron according to the present invention;

[0034] Figure 6 is a schematic diagram of the present invention after the polystyrene microspheres are melted;

[0035] Figure 7 is a schematic diagram of one end of an optical fiber after being processed according to the present invention;

[0036] Figure 8 It is a schematic diagram of the present invention in which the optical fiber is sealed with the injection needle and then inserted into the ultraviolet curing glue;

[0037] Fig. 9 It is a schematic diagram of curing the colloid in the optical fiber hole by irradiating the optical fiber with ultraviolet light in the present invention;

[0038] Fig.10It is a schematic diagram of the other end of the optical fiber after being processed in the present invention. DETAILED DESCRIPTION

[0039] The structure of the present invention is further described below with reference to the accompanying drawings and by way of examples. It should be noted that the present examples are descriptive rather than restrictive.

[0040] A method for making a fiber optic optical fluid channel, see Figure 1-10 , including the following steps:

[0041] Step 1. Use a selective filling method based on polystyrene microspheres and paraffin oil to process one end of the optical fiber. First, take a section of microstructured optical fiber of appropriate length, remove the coating at both ends, cut the end face flat, and place it vertically under a microscope for use. At the same time, sprinkle the polystyrene microspheres 1 on a glass slide and place them on the microscope stage. After that, use the tapered capillary probe 2 as a tool to operate the polystyrene microspheres. The tapered capillary probe can be drawn using an optical fiber melting taper machine. Fix the two ends of the silica capillary on the taper machine fixture. While heating the middle part of the capillary with an oxyhydrogen flame, pull the two ends of the capillary in the opposite direction at a uniform speed through the fixture to make the middle part of the capillary thinner to form a taper area. When the diameter of the capillary taper area is equivalent to the required microsphere diameter, stop heating and tapering. At this time, the thinnest part of the taper area is solid silica material. Cut the capillary at the thinnest part of the taper area to obtain two capillary probes. The tapered capillary probe is fixed on the three-dimensional displacement stage, and the three-dimensional micro-displacement platform is adjusted to make it contact with polystyrene microspheres of appropriate size. Under the action of electrostatic adsorption, the capillary probe can adsorb the microspheres, so that the selected microspheres can be picked up by the capillary probe, such as Figure 1 and Figure 2 Next, the microsphere is placed on the upper end face of the microstructured optical fiber 3 by adjusting the three-dimensional platform, and then the position of the microsphere is fine-tuned by using a probe to accurately place it on the selected fluid channel port, as shown in FIG. Figure 3 and 4 Then, fix the handle of the electric soldering iron 4 on the fixture of the three-dimensional displacement platform, control the soldering iron tip to approach the polystyrene microspheres to heat them, and fine-tune the position of the soldering iron tip during the heating process. After the microspheres melt, wait for the liquid to flow into the air holes slightly before removing the soldering iron tip. After cooling, a short section (L1, L1 = 1-2 mm) in the channel will be blocked by the solidified polystyrene 5, as shown in FIG. Figure 5 and Figure 6As shown. Finally, immerse one end of the processed optical fiber in the heated and melted paraffin oil and take it out after about ten seconds. Under the capillary effect, the paraffin oil 6 will be sucked into the remaining unblocked air holes to form a liquid column with a length of L2 (L2>L1, L2≈1cm). Since the melting point of paraffin is relatively low, polystyrene will not melt during the process of immersing the optical fiber in the paraffin oil, and the paraffin oil will not enter the selected fluid channel. After the paraffin oil solidifies, a section of the optical fiber with a length of L (L2>L>L1) is cut off at this end, so that one port of the selected fluid channel is exposed, and the remaining micropores are blocked by paraffin, as shown in FIG. Figure 7 shown.

[0042] Step 2: Use UV curing glue to seal the other end

[0043] First, insert one end of the optical fiber processed in the previous stage into the syringe needle 7, and then drip paraffin oil onto the needle tip to achieve a sealing effect, so that the optical fiber and the syringe needle are sealed and connected. Figure 8 As shown. Afterwards, a UV curing glue 8 with a relatively low viscosity (20 mPa·s) is selected as a plugging material, and while slowly injecting air into the fluid channel using a syringe, the end of the optical fiber to be plugged is inserted deeply into the UV curing glue. By injecting gas, the UV curing glue can enter the air hole to be plugged, but the fluid channel will not be affected. After about one minute, the optical fiber is removed from the UV curing glue, and the excess colloid on the surface of the optical fiber is wiped off before the optical fiber is removed from the needle. During this process, it should be ensured that air is always injected into the fluid channel. Finally, as shown in Fig. 9 As shown, ultraviolet light 9 is used to irradiate the optical fiber to solidify the colloid in the optical fiber hole, and then a small section of the optical fiber at this end is cut off. Fig.10 As shown, it can be observed that except for the fluid channel port, all other air holes have been blocked by the solidified UV curing glue. At this point, the fluid channel in the microstructured optical fiber is completed. In addition, this method can be used to make multiple fluid channels in the optical fiber.

[0044] The manufacturing method is suitable for manufacturing a single fluid channel and can also be used for manufacturing multiple fluid channels.

[0045] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for manufacturing an optical fiber optical fluid channel, characterized in that: The steps include: Step 1: A port at one end of a fluid channel is made at one end of a microstructured optical fiber by using a selective filling method based on polystyrene microspheres and paraffin oil; Step 2: When one end of the microstructured optical fiber is ventilated, a UV curing adhesive is used to seal the other end of the optical fiber except for the port corresponding to the fluid channel, so as to make the other end port of the fluid channel; Step 1 includes: 1.1 Select a microstructured optical fiber, pre-treat both ends of the optical fiber, and place the optical fiber vertically under a microscope for standby use; 1.

2. Use a tapered capillary probe to suck up the polystyrene microspheres sprinkled on the microscope stage, move them to the upper end surface of the microstructured light, and accurately place them on the selected fluid channel port; 1.

3. Heat the polystyrene microspheres with an electric soldering iron, and remove the soldering iron tip after the melted part of the microspheres flows into the air holes; 1.

3. After the molten polystyrene liquid cools down, immerse one end of the processed optical fiber in the heated and melted paraffin oil. Under the capillary effect, the paraffin oil is absorbed into the remaining unblocked air holes. The length of the liquid column of the absorbed paraffin oil needs to be greater than the length of the polystyrene column entering the air hole. 1.

4. After the paraffin oil solidifies, cut off a section of the end. The cut length needs to be less than the column length of the inhaled paraffin oil and greater than the length of the polyethylene column, so that one end of the selected fluid channel is exposed and the remaining micropores are blocked by paraffin; Step 2 includes: 2.

1. Insert one end of the optical fiber processed in step 1 into the syringe needle, and drop paraffin oil onto the needle tip to achieve a sealing effect, so that the optical fiber is sealed and connected to the syringe needle; 2.

2. While slowly injecting air into the fluid channel using a syringe, place the end of the optical fiber to be blocked deeply into the UV-curing glue with lower viscosity. Under the action of capillary effect, the glue is sucked into the air hole to be blocked at the end to be blocked; 2.

3. Take the optical fiber out of the UV curing glue, wipe off the excess glue on the surface of the optical fiber, and then take the optical fiber out of the needle; 2.

4. Use ultraviolet light to irradiate the optical fiber to solidify the colloid in the optical fiber hole, and then cut off a small section of the optical fiber at this end, so that all air holes except the fluid channel port are blocked by solidified ultraviolet curing glue.

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