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CN-121978796-A - Polarization-maintaining hollow anti-resonance optical fiber suitable for laser transmission and broadband communication

CN121978796ACN 121978796 ACN121978796 ACN 121978796ACN-121978796-A

Abstract

The invention relates to a polarization-maintaining hollow anti-resonance optical fiber suitable for laser transmission and broadband communication, which comprises an elliptical fiber core (1), an outermost sleeve (7) and a cladding region, wherein the elliptical fiber core (1) is internally filled with air, the cladding region comprises an x-direction structure and a y-direction structure, the x-direction structure comprises at least one first cladding layer, the y-direction structure is vertically symmetrical relative to a central axis of the x-direction structure and is divided into an upper half part and a lower half part, the upper half part and the lower half part respectively comprise at least one second cladding layer, the first cladding layer comprises a first cladding layer (2), a second cladding layer (3) and a third cladding layer (4), and the second cladding layer comprises an inner cladding layer (5) and an outer cladding layer (6). The invention can realize polarization and low-loss energy transmission in 1080nm high-energy transmission wave band, and has wide application prospect in the aspects of communication, sensing, high-energy polarization laser transmission and the like.

Inventors

  • HOU ZHIYUN
  • XU HONGXIANG
  • WANG WENTING
  • WU XIANGBIAO
  • WU DONGXIN
  • ZHOU GUIYAO
  • XIA CHANGMING

Assignees

  • 华南师范大学

Dates

Publication Date
20260505
Application Date
20260109

Claims (9)

  1. 1. A polarization-maintaining hollow anti-resonance optical fiber suitable for laser transmission and broadband communication comprises an elliptical fiber core (1), an outermost sleeve (7) and a cladding region, and is characterized in that, The inside of the elliptical fiber core (1) is filled with air; The cladding region comprises an x-direction structure and a y-direction structure, the x-direction structure is symmetrical relative to a central axis of the y-direction structure, the x-direction structure comprises a left half part and a right half part, the right half part has the same structure as the left half part and comprises at least one first cladding layer, the y-direction structure is symmetrical up and down relative to a central axis of the x-direction structure and is divided into an upper half part and a lower half part, and the upper half part and the lower half part comprise at least one second cladding layer; The first cladding comprises three nested circular structures, each of the three nested circular structures comprises a first cladding pipe (2), a second nested cladding pipe (3) and a third nested cladding pipe (4), the three nested circular structures are arranged in a triangular mode to form 3 supporting points, and the first cladding pipe (2) and the third nested cladding pipe (4) are intersected at one point of an outermost layer sleeve (7); The second cladding comprises two nested circular structures, wherein the two nested circular structures comprise an inner nested cladding pipe (5) and an outer nested cladding pipe (6), and the two nested circular structures are intersected at one point of the outermost sleeve (7); the adjacent cladding regions are not contacted with each other.
  2. 2. A polarization maintaining hollow-core antiresonant fiber suitable for laser transmission and broadband communication according to claim 1, characterized in that the material of the first cladding, the second cladding and the outer cladding (7) is quartz glass, fluoride glass, sulfide glass or silicate glass.
  3. 3. The polarization-maintaining hollow-core antiresonant optical fiber suitable for laser transmission and broadband communication according to claim 1, wherein the thickness of the first cladding tube (2) is 0.6-0.9 μm, the thickness of the second and third cladding tubes (3, 4) is 0.3-0.5 μm, and the thickness of the inner cladding tube (5, 6) is 0.3-0.55 μm.
  4. 4. A polarization maintaining hollow-core antiresonant fiber suitable for laser transmission and broadband communication according to claim 1, characterized in that the number of the outermost sleeves (7) is 2-3 layers.
  5. 5. A polarization maintaining hollow-core antiresonant fiber suitable for laser transmission and broadband communication according to claim 1, characterized in that the diameter of the first cladding tube (2) is larger than the diameter of the inner nested cladding tube (5).
  6. 6. A polarization maintaining hollow-core antiresonant optical fiber suitable for laser transmission and broadband communication according to claim 1, characterized in that the refractive index of the first cladding tube (2), the second cladding tube (3) and the third cladding tube (4) are all equal.
  7. 7. A polarization maintaining hollow-core antiresonant fiber suitable for laser transmission and broadband communication according to claim 1, characterized in that the first cladding tube (2) has a wall thickness difference from the inner nested cladding tube (5) so as to introduce high birefringence.
  8. 8. A polarization maintaining hollow-core antiresonant optical fiber suitable for laser transmission and broadband communication according to claim 1, characterized in that the major axis of the elliptic core (1) is Da, the minor axis is Db, the ellipticity of the elliptic core (1) is η, η = Db/Da, η is 0.3-0.9.
  9. 9. A polarization-maintaining hollow-core antiresonant optical fiber suitable for laser transmission and broadband communication according to claim 1, characterized in that the hollow-core antiresonant optical fiber has a diameter of 90-120 μm and an outer cladding (7) thickness of 12-18 μm.

Description

Polarization-maintaining hollow anti-resonance optical fiber suitable for laser transmission and broadband communication Technical Field The invention relates to the technical field of optical fibers, in particular to a polarization-preserving hollow anti-resonance optical fiber suitable for laser transmission and broadband communication. Background Hollow fiber (Hollow Core Fiber, HCF) represents an innovative solution to fiber technology, and aims to improve the information transmission efficiency of fiber communication and break through the limitation of traditional fiber in performance. Such fibers mainly include Bragg fibers, kagome fibers, hollow-core photonic bandgap fibers, hollow-core antiresonant fibers, and the like. They have in common that the core is filled mainly with a low refractive index substance, such as air, while the cladding adopts a periodic or antiresonant structure and contains some air fraction. These structures limit the propagation of light in the core by photonic bandgap effects or antiresonant effects, thereby achieving excellent loss and dispersion characteristics. The hollow anti-resonance optical fiber is widely applied to the fields of signal transmission, precision sensing, optical fiber gyroscopes and the like by virtue of low loss, low time delay, low nonlinearity and the like. Polarization maintaining performance is an important property of hollow-core antiresonant fibers, and is generally measured by phase birefringence, which is defined as the difference in the effective refractive index of the fundamental mode of the two polarization states. The light guiding passband of an antiresonant fiber is generally affected by the thickness of the cladding, and cladding of different thicknesses will cause the antiresonant reflection order to change, thereby causing the antiresonant bands to coincide. Proper adjustment of cladding wall thicknesses in mutually perpendicular directions can change the polarization modes of the polarization states in orthogonal directions, resulting in mode field differences, thus creating high birefringence. With the rapid development of optical fiber technology, the requirements on the performance of optical fibers are increasingly increased. In the fields of industrial processing, medical cosmetology and the like, an optical fiber is required to be capable of stably transmitting high-power laser (such as 1080 nm-band Yb laser). Meanwhile, in the field of optical fiber communication (such as S, C, L, U wave bands), and in the fields of optical fiber sensing, quantum communication and the like, not only is the optical fiber required to have low loss and wide bandwidth characteristics, but also the optical fiber is often required to have excellent polarization maintaining capability so as to stabilize the polarization state of a transmission signal. Currently, the dominant technology for achieving polarization maintaining of optical fibers is solid polarization maintaining optical fibers, such as panda-type or bow tie type optical fibers. However, its actual structure presents an inherent technical bottleneck. Firstly, the material has strong nonlinear effect, is easy to generate nonlinear effect and even cause damage under high power, limits the power transmission capacity, secondly, the transmission loss of the material is close to the theoretical limit of the material, further reduces the difficulty greatly, and in addition, the bandwidth of the material is usually limited, so that the near infrared high-power wave band and the communication wave band are difficult to cover simultaneously. The hollow anti-resonance fiber (HC-ARF) has the advantages that the light field is mainly conducted in the air, the material limit of the traditional solid fiber is fundamentally overcome, the extremely low nonlinear effect, the high damage threshold and the potential ultra-low loss are shown, and the hollow anti-resonance fiber becomes an ideal solution for the application. Although research on polarization-maintaining hollow-core antiresonant optical fibers has progressed, existing designs are mostly limited to communication bands, resulting in a single functionality. In order to meet the application requirements of integration of high-power laser transmission and broadband communication, an optical fiber design scheme capable of covering 1080nm and other high-power wave bands and S+C+L+U communication wave bands and combining low loss and high polarization maintaining characteristics is urgently required. In order to solve the technical bottleneck, the invention aims to provide the polarization-maintaining hollow anti-resonance optical fiber. The fiber successfully realizes the functions of high polarization maintaining property, low transmission loss and wide working bandwidth in 1080nm high-energy transmission wave band and S, C, L, U communication wave band through a synergistic scheme combining differential wall thickness design and special cladding m