CN-121978794-A - Optical fiber, preparation method thereof and all-fiber phase retarder

CN121978794ACN 121978794 ACN121978794 ACN 121978794ACN-121978794-A

Abstract

An optical fiber, a preparation method thereof and an all-fiber phase retarder belong to the technical field of optical fibers. The optical fiber comprises a fiber core and a cladding, wherein the cladding comprises a plurality of air holes which are circumferentially and periodically distributed around the fiber core, the fiber core is positioned at the center of the cladding, each air hole extends along the axial direction of the optical fiber and penetrates through two ends of the optical fiber, the inner wall of part of the air holes is provided with a transition metal chalcogenide layer as a first air hole, the rest of the air holes are used as second air holes, the number of the first air holes is at least two, and the first air holes are symmetrically distributed on two sides of the fiber core by taking the fiber core as a symmetrical center. By introducing the birefringence effect and enhancing the birefringence effect through the arrangement, controllable birefringence and beat length optimization can be realized, compared with the traditional optical fiber retarder manufacturing process, the length dependence of polarization regulation is reduced, the optical fiber retarder is easy to integrate with an optical fiber system, and the optical fiber environment stability is better.

Inventors

ZHONG DING
LIU KAIHUI
ZHOU XU
LIU CAN
XUE GUODONG

Assignees

中国人民大学

Dates

Publication Date: 20260505
Application Date: 20250116

Claims (10)

1. An optical fiber, characterized by comprising a fiber core and a cladding, wherein the cladding comprises a plurality of air holes which are circumferentially and periodically distributed around the fiber core, the fiber core is positioned at the center of the cladding, and each air hole extends along the axial direction of the optical fiber and penetrates through two ends of the optical fiber; Wherein, the inner wall of part of the air holes is provided with a transition metal chalcogenide layer as a first air hole, and the rest air holes are used as a second air hole; the number of the first air holes is at least two, and the first air holes are symmetrically distributed on two sides of the fiber core by taking the fiber core as a symmetrical center.
2. The optical fiber according to claim 1, wherein the number of the first air holes is at least 4, and the first air holes are sequentially arranged from inside to outside in a radial direction of the optical fiber; wherein the first air hole located at the innermost side is disposed adjacent to the core, or The first air holes positioned at the innermost side and the fiber cores are separated by 1-2 second air holes.
3. The optical fiber of claim 1, wherein the number of first air holes is two; wherein each of the first air holes is disposed adjacent to the core, or Each of the first air holes is spaced from the core by 1-2 of the second air holes.
4. An optical fiber according to any one of claims 1 to 3, wherein an end face of the optical fiber has an X-axis direction and a Y-axis direction perpendicular to each other and intersecting the core, and a plurality of the first air holes are arranged at intervals along the X-axis direction or the Y-axis direction; optionally, the optical fiber is a photonic crystal fiber; Optionally, the optical fiber is made of quartz or quartz polymer.
5. An optical fiber according to any one of claims 1 to 3, wherein the transition metal chalcogenide layer is a single layer, and/or, The composition of the transition metal chalcogenide layer includes at least one of MoS 2 、MoSe 2 、MoTe 2 、WS 2 、WSe 2 、WTe 2 、MoS x Se 2-x 、MoS x Te 2-x 、MoTe x Se 2-x 、WS x Se 2-x 、WS x Te 2-x 、WTe x Se 2-x , where 0< x <2.
6. A method of making an optical fiber comprising the steps of: The method comprises the steps that a bare optical fiber is obtained, the bare optical fiber comprises a fiber core and a cladding, the cladding comprises a plurality of air holes which encircle the fiber core and are distributed periodically, the fiber core is located at the center of the cladding, each air hole extends along the axial direction of the optical fiber and penetrates through two ends of the optical fiber, part of the air holes serve as target air holes for coating, the rest of the air holes serve as second air holes, the number of the target air holes is at least two, and the target air holes are symmetrically distributed on two sides of the fiber core by taking the fiber core as a symmetrical center; Physically adsorbing a metal mask on two end surfaces of the bare optical fiber to block the second air hole and expose the target air hole to obtain a blocked optical fiber; Placing one end of the plugging optical fiber into an aqueous solution of a transition metal source, and enabling the transition metal source solution to be adsorbed in the target air hole to obtain an infiltrated optical fiber; And performing chemical vapor deposition reaction by taking a sulfur source and a transition metal source in the infiltrated optical fiber as raw materials to grow a transition metal chalcogenide layer on the inner wall of the target air hole to form a first air hole, and decomposing the metal mask to obtain the optical fiber.
7. The method of manufacturing according to claim 6, wherein the step of physically adsorbing the metal mask to both end surfaces of the bare optical fiber to block the second air holes comprises: forming a patterned metal coating on the surface of a first hard substrate, wherein the patterned metal coating is provided with an exposure area corresponding to the target air hole and a mask area corresponding to the second air hole, forming a low-melting-point polymer layer on one side of the patterned metal coating, which is away from the first hard substrate, and stripping the first hard substrate to form a first film layer; attaching the patterned metal coating of the first film layer to a second hard substrate, removing the low-melting-point polymer layer through heat treatment, forming a high-melting-point polymer layer on one side of the patterned metal coating, which is far away from the second hard substrate, wherein the bonding force of the high-melting-point polymer layer is smaller than that of the low-melting-point polymer layer, and stripping the second hard substrate to form a second film layer; and respectively attaching the two end surfaces of the bare optical fiber with the patterned metal coating of the second film layer, preserving heat at 150-300 ℃ for 2-5 min, and removing the high-melting-point polymer layer through heat treatment, so that the mask region is physically adsorbed on the two end surfaces of the bare optical fiber to form the metal mask, and thus the plugged optical fiber is obtained.
8. The method of claim 7, wherein the material of the low-melting polymer layer comprises polymethyl methacrylate or polypropylene carbonate, and the material of the high-melting polymer layer comprises polypropylene carbonate; optionally, the step of removing the low melting point polymer layer by heat treatment and the step of removing the high melting point polymer layer by heat treatment respectively include: Soaking in acetone for 2-4 h, drying at room temperature, placing in a furnace chamber, and annealing at 400-420 ℃ for 3-5 h under the condition that the atmosphere in the furnace chamber is inert and the pressure in the furnace chamber is 30-50 Pa.
9. The method according to any one of claim 6 to 8, wherein, The transition metal source comprises at least one of Na 2 MoO 4 、K 2 MoO 4 、Na 2 WO 4 and K 2 WO 4 , and/or, The sulfur source comprises at least one of elemental sulfur, elemental selenium and elemental tellurium, and/or, The transition metal chalcogenide layer is a single layer.
10. An all-fiber phase retarder, characterized in that it is produced from an optical fiber according to any of claims 1 to 5, or an optical fiber produced by the production method according to any of claims 6 to 9.

Description

Optical fiber, preparation method thereof and all-fiber phase retarder Technical Field The application relates to the technical field of optical fibers, in particular to an optical fiber, a preparation method thereof and an all-fiber phase retarder. Background In all-fiber systems, polarization state manipulation is a key technology for achieving a variety of optical applications, such as mode-locked fiber lasers, optical communications, quantum information processing, and the like. Currently, a length of birefringent fiber (e.g., polarization maintaining fiber) is typically used as a phase retarder to manipulate the polarization state of an all-fiber system, and the birefringence effects in the fiber are typically introduced by designing the fiber geometry or introducing asymmetric stresses. However, the optical fiber has the following problems that 1, the performance of the traditional optical fiber phase retarder is easily affected by temperature change, mechanical deformation and the like due to the sensitivity of geometric and stress birefringence to the external environment, so that the polarization control is unstable, 2, the manufacturing process of the optical fiber is complex, the optical fiber involves fine structural design and material treatment, the cost is high, and the optical fiber is difficult to apply in large scale in actual production, and 3, the birefringent optical fiber based on geometric or stress usually has extremely short beat length (millimeter level), and the difficulty of precise cutting and welding operation in the integration process with an all-optical fiber system is greatly increased. Disclosure of Invention The present application provides an optical fiber, a method of manufacturing the same, and an all-fiber phase retarder for improving at least one of the above-mentioned technical problems. Embodiments of the present application are implemented as follows: In a first aspect, an example of the present application provides an optical fiber, including a core and a cladding, the cladding including a plurality of air holes circumferentially surrounding the core and periodically distributed, the core being located at a central position of the cladding, each air hole extending along an axial direction of the optical fiber and penetrating both ends of the optical fiber; Wherein, the inner wall of part of the air holes is provided with a transition metal chalcogenide layer as a first air hole, and the rest air holes are used as a second air hole; The number of the first air holes is at least two, and the first air holes are symmetrically distributed on two sides of the fiber core by taking the fiber core as a symmetrical center. According to the optical fiber provided by the application, the transition metal chalcogenide layer is generated on the inner wall of the first air hole in the optical fiber, so that the propagation speed of the orthogonal polarization mode is changed, the birefringence effect is introduced, the birefringence effect is enhanced, the controllable birefringence and beat length optimization can be realized, and compared with the traditional optical fiber retarder manufacturing process, the length dependence of polarization regulation is reduced, the optical fiber is easy to integrate with an optical fiber system, and meanwhile, the optical fiber environment stability is better. In a second aspect, the present examples provide a method of preparing an optical fiber comprising the steps of: The method comprises the steps that a bare optical fiber is obtained, the bare optical fiber comprises a fiber core and a cladding, the cladding comprises a plurality of air holes which encircle the fiber core and are distributed periodically, the fiber core is positioned in the center of the cladding, each air hole extends along the axial direction of the optical fiber and penetrates through two ends of the optical fiber, part of the air holes serve as target air holes for coating, the rest of the air holes serve as second air holes, the number of the target air holes is at least two, and the target air holes are symmetrically distributed on two sides of the fiber core by taking the fiber core as a symmetrical center; Physically adsorbing a metal mask on two end surfaces of the bare optical fiber to block the second air holes and expose the target air holes to obtain a blocked optical fiber; Placing one end of the plugging optical fiber into the aqueous solution of the transition metal source to enable the transition metal source solution to be adsorbed in the target air hole, so as to obtain the infiltrated optical fiber; and performing chemical vapor deposition reaction by taking a sulfur source and a transition metal source in the infiltrated optical fiber as raw materials to grow a transition metal chalcogenide layer on the inner wall of the target air hole to form a first air hole, and decomposing a metal mask to obtain the optical fiber. According to the preparatio