A metal / dielectric terahertz hollow-core optical fiber and its continuous preparation method and device

Abstract

The present invention discloses a metal / dielectric terahertz hollow fiber and its continuous preparation method and device. The feature is that the method includes steps such as pretreatment of the dielectric tube, deposition of a metal coating on the outer surface of the dielectric tube, coating of a protective layer resin on the outer surface of the metal coating and completion of winding, etc., which can deposit and grow a metal high-reflection film on the outer surface of the dielectric tube with a continuous length, thereby realizing large-scale preparation of a metal / dielectric terahertz hollow waveguide. Compared with the prior art, the present invention has the advantages of good bending performance, low transmission loss, simple process, etc., effectively enhancing the bonding performance between the dielectric layer and the metal layer, improving the weather resistance and transmission effect of the optical fiber, realizing large-scale continuous preparation of metal / dielectric terahertz hollow fibers with unlimited length, effectively improving production efficiency and reducing production costs, expanding the application range of the metal / dielectric terahertz hollow fiber, and having great application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber preparation, in particular to a metal / dielectric terahertz hollow optical fiber, and a continuous preparation method and device thereof. Background Art

[0002] With the rapid development of terahertz technology, the application demands in the fields of imaging, detection, sensing, communication, etc. are increasing day by day. As an important link in terahertz technology, the transmission of terahertz waves has received extensive attention. It is extremely necessary to develop high-reliability optical fibers for terahertz wave transmission. So far, researchers have developed a variety of terahertz optical fibers including hollow metal waveguides, dielectric tube waveguides, photonic crystal fibers, and metal / dielectric hollow optical fibers. Among them, the metal / dielectric terahertz hollow optical fiber has received great attention due to its excellent characteristics such as simple structure, no end-face reflection, and adjustable low-loss transmission window. The preparation of traditional metal / dielectric hollow optical fibers is to introduce a reaction solution into a capillary structure tube in a fixed state to deposit a metal reflection film on its inner surface, and the film thickness shows a certain degree of gradient change (non-uniform) along the length direction of the capillary tube, which becomes one of the factors restricting the developed length of the optical fiber.

[0003] At present, there are many literature reports on the preparation of metal / dielectric hollow optical fibers by chemical liquid deposition method. However, the poor bonding effect between the dielectric layer and the metal layer restricts the transmission performance of the optical fiber to a certain extent. Treating the outer surface of the dielectric tube with plasma can effectively enhance the bonding performance between the metal layer and the dielectric layer, and improve the weather resistance and transmission effect of the optical fiber. However, there is no preparation method and device in the existing published reports that can continuously produce metal / dielectric hollow optical fibers with unlimited length on a large scale. This makes the current preparation cost of metal / dielectric hollow optical fibers high and the production efficiency extremely low. At the same time, the length of the optical fiber also restricts the prospect of its large-scale application. Summary of the Invention

[0004] The purpose of the present invention is to design a metal / dielectric terahertz hollow optical fiber, and a continuous preparation method and device thereof, aiming at the deficiencies of the prior art. A dielectric tube with an inner diameter of 1 - 10 mm is used as the dielectric layer of the hollow optical fiber, and a metal coating and a resin protection layer are successively arranged on its outer surface to form a metal / dielectric terahertz hollow optical fiber. Deposit a metal coating on the outer surface of the dielectric tube, coat a protective layer resin on the outer surface of the metal coating, and complete winding, so as to deposit and grow a metal high-reflection film on the outer surface of the dielectric tube with a continuous length, and a production device for continuously producing a metal / dielectric terahertz hollow waveguide with unlimited length, which has the advantages of continuous production, simple process, low production cost, high production efficiency, good bending performance, low transmission loss, etc., and preferably solves the problems of poor bonding performance between the dielectric layer and the metal layer and difficulty in large-scale continuous production, and has a wide application prospect.

[0005] The object of the present invention is achieved as follows: A metal / dielectric terahertz hollow fiber, characterized in that a dielectric tube with an inner diameter of 1 to 10 mm is used as the dielectric layer of the hollow fiber, and a metal coating and a resin protective layer are sequentially provided on its outer surface to form the metal / dielectric terahertz hollow fiber. The dielectric layer is polypropylene, polytetrafluoroethylene, polypropylene or cycloolefin copolymer with low terahertz absorption rate; the metal coating is a metal material of silver, copper or gold with high terahertz wave reflectivity; the resin protective layer is silicone rubber resin or acrylic resin; the thickness of the dielectric layer is 10 to 500 μm; the thickness of the metal coating is 100 to 2000 nm; the thickness of the resin protective layer is 100 to 2000 μm.

[0006] A continuous preparation method of a metal / dielectric terahertz hollow fiber, characterized in that the method specifically comprises the following steps:

[0007] Step a: Clean, dry and pre-treat the continuous-length dielectric tube with plasma gas, and seal both ends of the pre-treated dielectric tube with a sealing material.

[0008] Step b: Continuously pass the pre-treated dielectric tube through a dynamic liquid-phase chemical deposition reaction zone to deposit a metal coating on the outer surface of the dielectric tube.

[0009] Step c: Introduce the dielectric tube coated with a metal layer into a drying zone, and after drying, uniformly coat a viscous resin glue on the outer surface of the metal coating, and obtain a resin protective layer after curing.

[0010] Step d: Remove the seals at both ends of the dielectric tube and wind it up to complete the preparation of the metal / dielectric terahertz hollow fiber.

[0011] The dielectric tube is a polypropylene, polytetrafluoroethylene, polypropylene or cycloolefin copolymer tube with an inner diameter of 1 to 10 mm and a wall thickness of 10 to 500 μm; the metal coating is a metal material of silver, copper or gold with a coating thickness of 100 to 2000 nm; the material of the resin protective layer is silicone rubber resin or acrylic resin with a protective layer thickness of 100 to 2000 μm; the plasma gas is hydrogen, oxygen, argon or nitrogen.

[0012] A continuous preparation device for metal / dielectric terahertz hollow optical fiber, characterized in that it consists of a liquid-phase deposition metal reaction unit, a resin coating unit and a winding disc to form a continuous preparation device for metal / dielectric terahertz hollow optical fiber. The pretreated dielectric tube enters the liquid-phase deposition metal reaction unit and the resin coating unit in sequence through a guide wheel for the deposition of the metal coating and the resin coating of the protective layer. The liquid-phase deposition metal reaction unit includes: a deposition reaction cavity, a drying area, a peristaltic pump and a reaction solution; the resin coating unit includes: a resin coating cavity and a resin curing area; the dielectric tube is sent into the liquid-phase deposition metal reaction unit by a guide wheel, and metal particles are deposited on the surface of the dielectric tube in the deposition reaction cavity with the liquid-phase deposition solution sent into the reaction cavity by the peristaltic pump to form a metal coating, and then sent to the drying area for hot air drying; the resin coating unit uniformly coats the resin glue on the surface of the metal coating in the resin coating cavity for the sent dielectric tube to form a resin protective layer, and then sent to the resin curing area. The cured dielectric tube is a metal / dielectric terahertz hollow optical fiber, and is wound by a winding disc to realize the continuous production of metal / dielectric terahertz hollow optical fiber with unlimited length.

[0013] Compared with the prior art, the present invention has the advantages of good bending performance, low transmission loss, simple process, long continuous production length, etc. The plasma treatment of the dielectric tube effectively enhances the bonding performance between the dielectric layer and the metal layer, improves the weather resistance and transmission effect of the optical fiber, can realize the large-scale continuous preparation of metal / dielectric terahertz hollow optical fiber with unlimited length, effectively improves the production efficiency, reduces the production cost, further expands the application range of the metal / dielectric terahertz hollow optical fiber, and has great application prospects. Brief Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of a metal / dielectric terahertz hollow optical fiber;

[0015] Figure 2 It is a process flow diagram of a preparation method for metal / dielectric terahertz hollow optical fiber;

[0016] Figure 3 It is a schematic diagram of a preparation device for metal / dielectric terahertz hollow optical fiber. Detailed Embodiments

[0017] Refer to Figure 1 , in the present invention, a dielectric tube with an inner diameter of 1 - 10 mm is used as the dielectric layer 110 of the hollow optical fiber, and a metal coating 120 and a resin protective layer 130 are sequentially arranged on its outer surface to form a metal / dielectric terahertz hollow optical fiber. The dielectric tube 110 is a polypropylene, polytetrafluoroethylene, polypropylene or cycloolefin copolymer tube with low terahertz absorption rate; the metal coating 120 is a metal material of silver, copper or gold with high terahertz wave reflectivity; the resin protective layer 130 is silicone rubber or acrylic resin.

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] Embodiment 1

[0020] Referring to Figure 2 , the continuous preparation of the metal / dielectric terahertz hollow fiber of the present invention specifically includes the following steps:

[0021] S1: Pretreat the outer surface of the dielectric tube, including cleaning, drying and plasma treatment.

[0022] In this step, the inner diameter of the preferred dielectric tube is 1-10 mm, the thickness of the dielectric layer is 100-500 μm, the gases used in the plasma treatment include but are not limited to hydrogen, oxygen, argon and nitrogen, and the plasma treatment time is 3-30 min.

[0023] S2: Prepare a metal coating on the outer surface of the dielectric tube by chemical liquid deposition and dry it.

[0024] In this step, a reaction liquid is introduced into the reaction chamber by a peristaltic pump. The reaction liquid reacts in the reaction chamber to generate metal atoms that deposit on the outer surface of the dielectric tube to form a metal coating; the reaction waste liquid is discharged from the lower end of the chamber, and the dielectric tube with the deposited metal layer enters the drying area through the lower end of the chamber; in the drying area, the sample is dried by heating and ventilation.

[0025] S3: Coat a resin protective layer on the outer surface of the metal coating and cure and dry it.

[0026] In this step, the dielectric tube with the metal layer deposited on its surface enters the protective layer resin coating chamber after drying, and the sample with the protective layer resin coated on its surface enters the protective layer resin curing area through the lower end of the chamber; in the curing area, the sample is cured and dried by ultraviolet curing and heating and ventilation.

[0027] S4: Wind up and complete the preparation of the metal / dielectric terahertz hollow fiber.

[0028] Referring to Figure 3, the continuous preparation device of the metal / dielectric terahertz hollow fiber of the present invention includes: a liquid-phase deposition metal reaction unit 310, a protective layer resin coating unit 320, and a winding reel 330; wherein, the pretreated dielectric tube 350 enters the liquid-phase deposition metal reaction unit 310 after passing through the guide pulley 340. The dielectric tube 350 deposits a metal coating on its surface and enters the protective layer resin coating unit 320 after drying. After successfully coating the protective layer resin and curing, it is wound by the winding reel 330 to complete the preparation of the metal / dielectric terahertz hollow fiber.

[0029] The liquid-phase deposition metal reaction unit 310 includes: a deposition reaction cavity 311, a drying area 312, a peristaltic pump 313, and a reaction solution 314; the peristaltic pump 313 pumps the reaction solution 314 into the deposition reaction cavity 311, and a metal coating is deposited on the outer surface of the dielectric tube 350 in the deposition reaction cavity 311 and dried by the drying area 312.

[0030] The protective layer resin coating unit 320 includes: a resin coating cavity 321 and a resin curing area 322; the dielectric tube 350 with a metal layer deposited on its surface after drying enters the resin coating cavity 321, and a protective layer resin solution is evenly coated on the surface of the metal layer, and then enters the resin curing area 322 for curing and drying.

[0031] The action mechanism and advantages of the above metal / dielectric terahertz hollow fiber are as follows: The outer surface of the dielectric tube is treated by plasma, which greatly improves the bonding performance between the dielectric layer and the metal layer and enhances the performance of the fiber. In addition, for the structure of the metal / dielectric terahertz hollow fiber, the traditional preparation method and system is to introduce a reaction solution into a capillary structure tube in a fixed state to deposit a metal reflection film on its inner surface, and the film thickness shows a certain degree of gradient change (non-uniform) along the length direction of the capillary tube, which becomes one of the factors restricting the developed length of the fiber. The present invention makes corresponding improvements to the traditional preparation method and device, enabling it to continuously produce metal / dielectric terahertz hollow fibers with unlimited length on a large scale.

[0032] The above-described embodiments only represent the best implementation mode of the present invention. The description is relatively detailed and specific, but it should not be construed as a limitation of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A metal / dielectric terahertz hollow fiber, characterized in that A medium tube with an inner diameter of 1 - 10 mm is used as the medium layer of the hollow fiber. A metal coating and a resin protective layer are successively provided on its outer surface to form a metal / medium terahertz hollow fiber. The medium tube is made of polypropylene, polytetrafluoroethylene, polypropylene or cycloolefin copolymer tubing with low terahertz absorption rate; the metal coating is made of metal materials such as silver, copper or gold with high terahertz wave reflectivity; the resin protective layer is silicone rubber or acrylic resin; the continuous preparation of the metal / medium terahertz hollow fiber specifically includes the following steps: Step a: Clean, dry and pretreat the continuous-length medium tube with plasma gas, and seal both ends of the pretreated medium tube with a sealing material. Step b: Continuously pass the pretreated medium tube through the dynamic liquid-phase chemical deposition reaction zone to deposit a metal coating on the outer surface of the medium tube. Step c: Introduce the medium tube coated with a metal layer into the drying zone. After drying, evenly apply a viscous resin glue solution on the outer surface of the metal coating, and obtain a resin protective layer after curing. Step d: Remove the seals at both ends of the medium tube and wind it up to complete the preparation of the metal / medium terahertz hollow fiber.

2. The metal / dielectric terahertz hollow fiber according to claim 1, wherein The medium tube is made of polypropylene, polytetrafluoroethylene, polypropylene or cycloolefin copolymer tubing with an inner diameter of 1 - 10 mm and a wall thickness of 10 - 500 μm.

3. The metal / dielectric terahertz hollow fiber according to claim 1, wherein The thickness of the metal coating is 100 - 2000 nm; the thickness of the resin protective layer is 100 - 2000 μm.

4. The metal / dielectric terahertz hollow-core optical fiber according to claim 1, wherein The plasma gas is hydrogen, oxygen, argon or nitrogen.

5. A continuous preparation device for the metal / dielectric terahertz hollow fiber according to claim 1, characterized in that, The device consists of a liquid-phase deposited metal reaction unit, a resin coating unit and a winding disk. The pretreated medium tube enters the liquid-phase deposited metal reaction unit and the resin coating unit in sequence through a guide wheel for the deposition of the metal coating and the resin coating of the protective layer. The liquid-phase deposited metal reaction unit includes: a deposition reaction cavity, a drying zone, a peristaltic pump and a reaction solution; the resin coating unit includes: a resin coating cavity and a resin curing zone; the medium tube is sent into the liquid-phase deposited metal reaction unit by a guide wheel, and reacts with the liquid-phase deposition solution sent into the reaction cavity by the peristaltic pump in the deposition reaction cavity to deposit metal particles on the surface of the medium tube. After forming a metal coating, it is sent into the drying zone for hot air drying; the resin coating unit evenly applies the resin glue solution on the surface of the medium tube sent into the resin coating cavity to form a resin protective layer, and then sends it into the resin curing zone. The cured medium tube is a metal / medium terahertz hollow fiber, and is wound up by the winding disk to realize the continuous production of the metal / medium terahertz hollow fiber with unlimited length.

6. The continuous preparation device for the metal / dielectric terahertz hollow optical fiber according to claim 5, characterized in that, The drying zone includes a heating device and a ventilation device, and the resin curing zone includes an ultraviolet curing device, a heating device and a ventilation device.

7. The continuous preparation device for the metal / dielectric terahertz hollow optical fiber according to claim 5, characterized in that, Elastic pressure buffer pads are provided in the contact areas between the deposition reaction cavity and the resin coating cavity and the medium tube.

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