A method for fabricating a hollow optical waveguide

Abstract

The application relates to a preparation method of a hollow core optical waveguide and belongs to the technical field of optical material preparation. After a conventional thermal ion exchange process is carried out, a deposition process is carried out by using hydrogen, hydrogen is transmitted into the reserved part by a hydrogen transmission machine, and then the overall environment temperature is increased to 250 DEG C-500 DEG C; hydrogen is used as a reducing agent, silver ions are given electrons by breaking hydrogen bonds at high temperature, and the silver ions buried in the inner wall are reduced into silver single elements to form a silver film. The hollow core optical waveguide is simple to manufacture, does not need to be applied to large equipment, and has relatively low process technical requirements and manufacturing cost.

Description

Technical Field

[0001] This invention relates to a method for fabricating a hollow optical waveguide, belonging to the field of optical material fabrication technology. Background Technology

[0002] In recent years, hollow-core optical waveguides have seen a wide range of applications, primarily including spectral gas sensing, optical sensing, fiber optic communication, and optical devices. Furthermore, different types of optical waveguides, such as silver-plated / silver iodide-based hollow-core waveguides, photonic bandgap hollow-core waveguides, and substrate-integrated hollow-core waveguides, have been extensively studied and applied in environmental monitoring, breath diagnostics, and industrial process detection and control. Simultaneously, the market will place higher demands on the manufacturing processes and product performance of hollow-core optical waveguides.

[0003] The fabrication of conventional hollow optical waveguides typically involves an internal electroplating process after stretching, which usually uses toxic and harmful electroplating solutions, causing environmental pollution during the process. In addition, conventional electroplating technology usually requires large-scale electroplating equipment. In terms of cost, conventional electroplating technology requires expensive electroplating solutions and equipment. Furthermore, in terms of the final product, conventional electroplating films have poor uniformity, resulting in uneven depths of color.

[0004] In view of the aforementioned shortcomings, the inventor actively researched and innovated to create a method for fabricating hollow optical waveguides, making them more industrially viable. This design employs a deposition process using hydrogen as a reducing agent, requiring only the use of equipment to fill the raw materials with hydrogen and raising the ambient temperature of the process environment. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a hollow optical waveguide and its fabrication method. The present invention employs a deposition process, utilizing a device to fill a stretched hollow optical waveguide with hydrogen gas, raising the ambient temperature, and using the hydrogen gas as a reducing agent to reduce silver ions embedded in the raw materials through thermal ion exchange into a silver thin film, forming it on the inner wall of the hollow optical waveguide. The waveguide is then cut as needed to obtain the completed hollow optical waveguide.

[0006] The present invention discloses a method for fabricating a hollow optical waveguide, the specific fabrication steps of which are as follows:

[0007] S1. Prepare a cylindrical raw material with a hollow section in the middle, stretch the raw material to obtain a stretched hollow optical waveguide with a hollow section in the middle.

[0008] S2. Connect the stretched hollow optical waveguide, the molten salt extraction device, and the thermal ion exchange device through a liquid guiding hose. Extract the molten salt from the thermal ion exchange device through the molten salt extraction device and pass it through the empty part of the hollow optical waveguide for thermal ion exchange reaction. Bury the silver ions into the inner wall of the empty part of the hollow optical waveguide. Repeat this process until the thermal ion exchange reaction is completed.

[0009] S3. The hollow optical waveguide after the thermal ion exchange process, a hydrogen transporter, and hydrogen are connected in series through a pipeline. The hydrogen transporter delivers hydrogen to the empty part of the hollow optical waveguide after the thermal ion exchange process. The process environment temperature is stabilized at 250℃-500℃. After the deposition process, a silver film with a thickness of 10μm-50μm is formed on the inner wall of the empty part of the hollow optical waveguide after the thermal ion exchange process. Hydrogen acts as a reducing agent. After breaking the hydrogen bonds at high temperature, it gives electrons to silver ions, reducing the silver ions buried in the inner wall to elemental silver to form a silver film.

[0010] S4. After the deposition process is completed, the hollow optical waveguide fabrication process is finished. Then, the hollow optical waveguide is cut as needed to obtain the required length of hollow optical waveguide.

[0011] Furthermore, the raw material mentioned in S1 is silicon dioxide; the raw material is a hollow columnar body with a radius of 0.2cm to 2cm, and the empty part in the middle is cylindrical with a radius of 0.2mm to 2mm.

[0012] Furthermore, the radius of the stretched hollow waveguide in S1 is 0.8mm-1.2mm; the radius of the hollow waveguide with the empty portion is 0.5μm-2μm.

[0013] Furthermore, the liquid guiding hose described in S2 is disconnected when it passes through the hollow portion of the stretched hollow optical waveguide, and the molten salt is directly exchanged through the hollow portion of the hollow optical waveguide.

[0014] Furthermore, the thermal ion exchange temperature in S2 is 260℃~280℃, and the exchange time is 40~50min.

[0015] Furthermore, the fluid guiding hose described in S2 is made of either polytetrafluoroethylene or silicone.

[0016] Furthermore, the method for preparing the exchange molten salt described in S2 is as follows: sodium nitrate, calcium nitrate and silver nitrate are mixed by stirring in a molar percentage of 1:1:0.01 to prepare the thermal ion exchange molten salt.

[0017] By means of the above-described solution, the present invention has at least the following advantages:

[0018] This invention utilizes hydrogen deposition after a conventional thermal ion exchange process. Hydrogen is introduced into the empty section via a hydrogen transporter, and the overall ambient temperature is raised to 250°C–500°C. Hydrogen acts as a reducing agent, breaking hydrogen bonds at high temperature and donating electrons to silver ions, reducing the silver ions embedded in the inner wall to elemental silver to form a silver thin film. This hollow optical waveguide is simple to fabricate, does not require large-scale equipment, and has relatively low process requirements and manufacturing costs.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show a certain embodiment of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is an overall schematic diagram of the raw materials for fabricating the hollow optical waveguide of this invention;

[0022] Figure 2 This is an overall schematic diagram of the hollow optical waveguide of the present invention after stretching;

[0023] Figure 3 This is an overall schematic diagram of the hollow optical waveguide thermal ion exchange of the present invention;

[0024] Figure 4 This is an overall schematic diagram of the hollow optical waveguide deposition process of the present invention;

[0025] Figure 5 This is an overall schematic diagram of the hollow optical waveguide of the present invention after its fabrication is completed;

[0026] Figure 6 This is a cross-sectional view of the hollow optical waveguide of the present invention after it has been fabricated.

[0027] In the figure,

[0028] 11. The middle blank section; 12. Raw material preparation;

[0029] 21. The stretched hollow optical waveguide; 22. The empty portion of the hollow optical waveguide;

[0030] 31. Liquid delivery hose; 32. Molten salt extraction device; 33. Molten salt; 34. Thermo-ion exchange device;

[0031] 41. Hydrogen transmission machine; 42. Hollow-core optical waveguide after thermionic exchange process; 43. Hydrogen gas;

[0032] 51. Finished hollow optical waveguide; 52. Empty portion of hollow optical waveguide; 53. Silver thin film. Detailed Implementation

[0033] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0034] See Figures 1 to 6 The preferred embodiment of the present invention describes a method for fabricating a hollow optical waveguide, the specific fabrication steps of which are as follows:

[0035] like Figures 1 to 2 As shown: S1, prepare a cylindrical raw material 12 with a hollow part 11 in the middle, stretch the raw material 12 to obtain a stretched hollow optical waveguide 21 with a hollow optical waveguide hollow part 22.

[0036] The raw material 12 is made of silicon dioxide; the raw material 12 is a hollow column with a radius of 0.2 cm to 2 cm, and the empty part 11 in the middle is cylindrical with a radius of 0.2 mm to 2 mm;

[0037] The radius of the stretched hollow optical waveguide 21 is 0.8mm-1.2mm; the radius of the hollow optical waveguide empty portion 22 is 0.5μm-2μm.

[0038] like Figure 3 As shown: S2, the stretched hollow optical waveguide 21, the molten salt extraction device 32, and the thermionic exchange device 34 are connected by a liquid guiding hose 31. The liquid guiding hose 31 is disconnected when it passes through the hollow optical waveguide 21 with an empty portion 22. Molten salt 33 is directly passed through the empty portion 22 of the hollow optical waveguide. Molten salt 33 is extracted from the thermionic exchange device 34 by the molten salt extraction device 32 and passed through the empty portion 22 of the hollow optical waveguide for thermionic exchange reaction. Thermionic exchange temperature is 260℃~280℃ and exchange time is 40-50min. Silver ions are buried in the inner wall of the empty portion 22 of the hollow optical waveguide. This process is repeated until the thermionic exchange reaction is completed.

[0039] The fluid guiding hose 31 is made of either polytetrafluoroethylene or silicone.

[0040] The method for preparing the exchange molten salt 33 is as follows: sodium nitrate, calcium nitrate and silver nitrate are mixed by stirring in a molar percentage of 1:1:0.01 to prepare the thermal ion exchange molten salt;

[0041] like Figure 4 As shown: S3, the hollow optical waveguide 42 after the thermal ion exchange process, the hydrogen transporter 41, and the hydrogen 43 are connected in series through a pipeline. The hydrogen transporter 41 is used to transport the hydrogen 43 to the empty part of the hollow optical waveguide 42 after the thermal ion exchange process. The process environment temperature is stabilized at 250℃-500℃. After the deposition process, a silver film with a thickness of 10μm-50μm is formed on the inner wall of the empty part of the hollow optical waveguide 42 after the thermal ion exchange process. The hydrogen acts as a reducing agent. After breaking the hydrogen bonds at high temperature, it gives electrons to the silver ions, reducing the silver ions buried in the inner wall to elemental silver to form a silver film.

[0042] like Figure 5 and Figure 6 As shown, after the S4 deposition process is completed, the hollow optical waveguide fabrication process is finished. Then, the hollow optical waveguide is cut as needed to obtain the required length of hollow optical waveguide.

[0043] Example 1

[0044] S1. Prepare a cylindrical raw material 12 with a central empty portion 11, stretch the raw material 12 to obtain a stretched hollow optical waveguide 21 with a hollow optical waveguide empty portion 22.

[0045] The raw material 12 is made of silicon dioxide; the raw material 12 is a hollow column with a radius of 0.2 cm, and the empty part 11 in the middle is cylindrical with a radius of 0.2 mm;

[0046] The radius of the stretched hollow optical waveguide 21 is 0.8 mm; the radius of the hollow optical waveguide empty portion 22 is 0.5 μm.

[0047] S2. The stretched hollow optical waveguide 21, the molten salt extraction device 32, and the thermionic exchange device 34 are connected by a liquid guiding hose 31. The liquid guiding hose 31 is disconnected when it passes through the hollow optical waveguide 21 with an empty portion 22. Molten salt 33 is directly passed through the empty portion 22 of the hollow optical waveguide. Molten salt 33 is extracted from the thermionic exchange device 34 by the molten salt extraction device 32 and passed through the empty portion 22 of the hollow optical waveguide for thermionic exchange reaction. The thermionic exchange temperature is 260℃ and the exchange time is 40min. Silver ions are buried in the inner wall of the empty portion 22 of the hollow optical waveguide. This process is repeated until the thermionic exchange reaction is completed.

[0048] The fluid guiding hose 31 is made of polytetrafluoroethylene;

[0049] The method for preparing the exchange molten salt 33 is as follows: sodium nitrate, calcium nitrate and silver nitrate are mixed by stirring in a molar percentage of 1:1:0.01 to prepare the thermal ion exchange molten salt;

[0050] S3. The hollow optical waveguide 42 after the thermal ion exchange process, the hydrogen transporter 41, and the hydrogen gas 43 are connected in series through a pipeline. The hydrogen transporter 41 is used to transport the hydrogen gas 43 to the empty part of the hollow optical waveguide 42 after the thermal ion exchange process. The process environment temperature is stabilized at 250℃. After the deposition process, a silver film with a thickness of 10μm is formed on the inner wall of the empty part of the hollow optical waveguide 42 after the thermal ion exchange process. The hydrogen gas acts as a reducing agent. After breaking the hydrogen bonds at high temperature, it gives electrons to the silver ions, reducing the silver ions buried in the inner wall to elemental silver to form a silver film.

[0051] S4. After the deposition process is completed, the hollow optical waveguide fabrication process is finished. Then, the hollow optical waveguide is cut as needed to obtain the required length of hollow optical waveguide.

[0052] Example 2

[0053] S1. Prepare a cylindrical raw material 12 with a central empty portion 11, stretch the raw material 12 to obtain a stretched hollow optical waveguide 21 with a hollow optical waveguide empty portion 22.

[0054] The raw material 12 is made of silicon dioxide; the raw material 12 is a hollow column with a radius of 2 cm, and the empty part 11 in the middle is cylindrical with a radius of 2 mm;

[0055] The radius of the stretched hollow waveguide 21 is 1.2 mm; the radius of the hollow waveguide empty portion 22 is 2 μm.

[0056] S2. The stretched hollow optical waveguide 21, the molten salt extraction device 32, and the thermionic exchange device 34 are connected by a liquid guiding hose 31. The liquid guiding hose 31 is disconnected when it passes through the hollow optical waveguide 21 with an empty portion 22. Molten salt 33 is directly passed through the empty portion 22 of the hollow optical waveguide. Molten salt 33 is extracted from the thermionic exchange device 34 by the molten salt extraction device 32 and passed through the empty portion 22 of the hollow optical waveguide for thermionic exchange reaction. The thermionic exchange temperature is 280℃ and the exchange time is 50min. Silver ions are buried in the inner wall of the empty portion 22 of the hollow optical waveguide. This process is repeated until the thermionic exchange reaction is completed.

[0057] The fluid guiding hose 31 is made of polytetrafluoroethylene;

[0058] The method for preparing the exchange molten salt 33 is as follows: sodium nitrate, calcium nitrate and silver nitrate are mixed by stirring in a molar percentage of 1:1:0.01 to prepare the thermal ion exchange molten salt;

[0059] S3. The hollow optical waveguide 42 after the thermal ion exchange process, the hydrogen transporter 41, and the hydrogen gas 43 are connected in series through a pipeline. The hydrogen transporter 41 is used to transport the hydrogen gas 43 to the empty part of the hollow optical waveguide 42 after the thermal ion exchange process. The process environment temperature is stabilized at 250℃-500℃. After the deposition process, a silver film with a thickness of 50μm is formed on the inner wall of the empty part of the hollow optical waveguide 42 after the thermal ion exchange process. The hydrogen gas acts as a reducing agent. After breaking the hydrogen bonds at high temperature, it gives electrons to the silver ions, reducing the silver ions buried in the inner wall to elemental silver to form a silver film.

[0060] S4. After the deposition process is completed, the hollow optical waveguide fabrication process is finished. Then, the hollow optical waveguide is cut as needed to obtain the required length of hollow optical waveguide.

[0061] Example 3

[0062] S1. Prepare a cylindrical raw material 12 with a central empty portion 11, stretch the raw material 12 to obtain a stretched hollow optical waveguide 21 with a hollow optical waveguide empty portion 22.

[0063] The raw material 12 is made of silicon dioxide; the raw material 12 is a hollow column with a radius of 1.3 cm, and the empty part 11 in the middle is cylindrical with a radius of 1.2 mm;

[0064] The radius of the stretched hollow optical waveguide 21 is 1 mm; the radius of the hollow optical waveguide empty portion 22 is 1.3 μm;

[0065] S2. The stretched hollow optical waveguide 21, the molten salt extraction device 32, and the thermionic exchange device 34 are connected by a liquid guiding hose 31. The liquid guiding hose 31 is disconnected when it passes through the hollow optical waveguide 21 with an empty portion 22. Molten salt 33 is directly passed through the empty portion 22 of the hollow optical waveguide. Molten salt 33 is extracted from the thermionic exchange device 34 by the molten salt extraction device 32 and passed through the empty portion 22 of the hollow optical waveguide for thermionic exchange reaction. The thermionic exchange temperature is 270°C and the exchange time is 45 minutes. Silver ions are buried in the inner wall of the empty portion 22 of the hollow optical waveguide. This process is repeated until the thermionic exchange reaction is completed.

[0066] The fluid guiding hose 31 is made of either polytetrafluoroethylene or silicone.

[0067] The method for preparing the exchange molten salt 33 is as follows: sodium nitrate, calcium nitrate and silver nitrate are mixed by stirring in a molar percentage of 1:1:0.01 to prepare the thermal ion exchange molten salt;

[0068] S3. The hollow optical waveguide 42 after the thermal ion exchange process, the hydrogen transporter 41, and the hydrogen gas 43 are connected in series through a pipeline. The hydrogen transporter 41 is used to transport the hydrogen gas 43 to the empty part of the hollow optical waveguide 42 after the thermal ion exchange process. The process environment temperature is stabilized at 400℃. After the deposition process, a silver film with a thickness of 30μm is formed on the inner wall of the empty part of the hollow optical waveguide 42 after the thermal ion exchange process. The hydrogen gas acts as a reducing agent. After breaking the hydrogen bonds at high temperature, it gives electrons to the silver ions, reducing the silver ions buried in the inner wall to elemental silver to form a silver film.

[0069] S4. After the deposition process is completed, the hollow optical waveguide fabrication process is finished. Then, the hollow optical waveguide is cut as needed to obtain the required length of hollow optical waveguide.

[0070] Performance testing

[0071] The test results are as follows:

[0072] The hollow optical waveguide fabricated using the method in Example 1 was selected with a length of 1m. A connector was made, and UPC connectors were attached to both ends. One end was connected to a light source, and the other end to a testing instrument. After testing the insertion loss, the insertion loss was found to be 0.052dB, and the insertion loss of the hollow optical waveguide was 0.052dB / m. Upon completion of the test, the waveguide loss met the data requirements, and the fabrication method and apparatus of the hollow optical waveguide met the design requirements.

[0073] The hollow optical waveguide prepared using the method in Example 2 was selected with a length of 1m. A connector was made, and UPC connectors were attached to both ends. One end was connected to a light source, and the other end to a testing instrument. After testing the insertion loss, the insertion loss was found to be 0.035dB, and the insertion loss of the hollow optical waveguide was 0.035dB / m. After testing, the waveguide loss met the data requirements, and the fabrication method and apparatus of the hollow optical waveguide met the design requirements.

[0074] The hollow optical waveguide prepared using the method in Example 3 was selected with a length of 1m. A connector was made, and UPC connectors were attached to both ends. One end was connected to a light source, and the other end to a testing instrument. After testing the insertion loss, the insertion loss was found to be 0.04dB, and the insertion loss of the hollow optical waveguide was 0.04dB / m. After testing, the waveguide loss met the data requirements, and the fabrication method and apparatus of the hollow optical waveguide met the design requirements.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for fabricating a hollow optical waveguide, characterized in that: The specific preparation steps are as follows: S1. Prepare a cylindrical raw material with a hollow section in the middle, stretch the raw material to obtain a stretched hollow optical waveguide with a hollow section in the middle. S2. Connect the stretched hollow optical waveguide, the molten salt extraction device, and the thermal ion exchange device through a liquid guiding hose. Extract the molten salt from the thermal ion exchange device through the molten salt extraction device and pass it through the empty part of the hollow optical waveguide for thermal ion exchange reaction. Bury the silver ions into the inner wall of the empty part of the hollow optical waveguide. Repeat this process until the thermal ion exchange reaction is completed. S3. The hollow optical waveguide after the thermal ion exchange process, the hydrogen transporter, and the hydrogen are connected in series through a pipeline. The hydrogen transporter is used to transport hydrogen to the empty part of the hollow optical waveguide after the thermal ion exchange process. The process environment temperature is stabilized at 250℃-500℃. After the deposition process, a silver film with a thickness of 10μm-50μm is formed on the inner wall of the empty part of the hollow optical waveguide after the thermal ion exchange process. Hydrogen acts as a reducing agent. After breaking the hydrogen bonds at high temperature, it gives electrons to the silver ions, reducing the silver ions buried in the inner wall to elemental silver to form a silver film. S4. After the deposition process is completed, the hollow optical waveguide fabrication process is finished. Then, the hollow optical waveguide is cut as needed to obtain the required length of hollow optical waveguide.

2. The method for fabricating a hollow optical waveguide according to claim 1, characterized in that: The raw material described in S1 is silicon dioxide; the raw material is a hollow column with a radius of 0.2cm to 2cm, and the empty part in the middle is cylindrical with a radius of 0.2mm to 2mm.

3. The method for fabricating a hollow optical waveguide according to claim 1, characterized in that: The radius of the stretched hollow waveguide in S1 is 0.8mm-1.2mm; the radius of the hollow waveguide with the empty portion is 0.5μm-2μm.

4. The method for fabricating a hollow optical waveguide according to claim 1, characterized in that: The liquid guiding hose described in S2 is disconnected when it passes through the empty part of the stretched hollow optical waveguide, and the molten salt is directly exchanged through the empty part of the hollow optical waveguide.

5. The method for fabricating a hollow optical waveguide according to claim 1, characterized in that: The thermal ion exchange temperature in S2 is 260℃~280℃, and the exchange time is 40~50min.

6. The method for fabricating a hollow optical waveguide according to claim 1, characterized in that: The fluid guiding hose described in S2 is made of either polytetrafluoroethylene or silicone.

7. The method for fabricating a hollow optical waveguide according to claim 1, characterized in that: The method for preparing the molten salt for exchange described in S2 is as follows: sodium nitrate, calcium nitrate and silver nitrate are mixed by stirring at a molar percentage of 1:1:0.01 to prepare the thermal ion exchange molten salt.

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