Photonic crystal fiber with high birefringence characteristic

Abstract

A photonic crystal fiber with the high birefringence characteristic comprises a fiber core and a piece of cladding, wherein the fiber core is placed in the center of the photonic crystal fiber and is not provided with air vent holes. The cladding is composed of an inner cladding body and an outer cladding body. The inner cladding body which wraps the fiber core is provided with eight circular large air vent holes and four circular small air vent holes, wherein the eight circular large air vent holes are symmetrically distributed, and the four circular small air vent holes are arrayed in a rectangular mode and symmetrically distributed. The outer cladding body which wraps the inner cladding body comprises circular air vent holes, wherein the circular air vent holes of the outer cladding body are distributed according to grid nodes, namely, every three adjacent circular air vent holes are arrayed on the cross section of the photonic crystal fiber to form a regular triangle structure. The photonic crystal fiber has the advantages that the photonic crystal fiber is novel in structure, the photonic crystal fiber has double-rotation symmetry due to the fact that the structural arrangement of the photonic crystal fiber is changed, the photonic crystal fiber is very high in birefringence and high in nonlinear coefficient, the photonic crystal fiber can be used for manufacturing a polarization maintaining optical fiber which is nonlinear or has the polarization characteristic and for manufacturing other related optical fiber devices, due to the fact that the birefringence of the photonic crystal fiber is achieved when the physical dimension of the air vent holes is changed, the photonic crystal fiber is hardly influenced by the temperature and the pressure, and the photonic crystal fiber is good in stability and more suitable for application.

Description

technical field [0001] The invention belongs to the field of optical fiber technology, in particular to a photonic crystal optical fiber with high birefringence characteristics. Background technique [0002] In a single-mode fiber, the fundamental mode is composed of two mutually orthogonal polarization modes, which have the same propagation constant and are degenerate with each other, so they can be regarded as a single polarization electric vector. However, the actual optical fiber has some imperfections in the process of production, cabling, laying, etc., and the internal refractive index distribution is also uneven due to the uneven internal stress. These factors will cause the refractive index of the fiber to be unequal in different directions, that is, there are differences in the propagation constants of the two orthogonal polarization modes, which destroy the mutual degeneracy of the fundamental modes, resulting in mode birefringence. The polarization-maintaining f...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the deficiency of low birefringence caused by the existing optical fiber drawing technology, and provide a photonic crystal fiber with high birefringence characteristics that is simple in structure and easy to manufacture. The photonic crystal fiber structure itself has double rotational symmetry Higher birefringence than the existing birefringent photonic crystal fiber can be obtained, and the nonlinear coefficient is relatively high

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