Photonic crystal fiber

Abstract

The invention discloses a photonic crystal fiber. The photonic crystal fiber is characterized by comprising a core layer, a cladding layer and a coating layer from inside to outside, wherein the crosssection of the fiber is circular, the core layer, the cladding layer and the coating layer are concentric, the core layer is the inner-most layer of the fiber, the center of the cross section of thecore layer has a circular hole, the cladding layer is internally provided with multiple fan-shaped ring air holes uniformly, the cladding layer comprises four cladding rings, each cladding ring has same-size fan-shaped ring air holes, the air holes are sequentially adjacent, the sizes of the fan-shaped ring air holes of in the cladding rings gradually increase from inside to outside, intervals ofthe cladding rings are the same, the coating layer is the outer-most layer, the core layer and the cladding layer are respectively prepared from silica crystal or silicon crystal, and the coating layer is prepared from acrylate or silicone resin. The photonic crystal fiber is advantaged in that multiple orbital angular momentum modes can be transmitted, effective refractive index difference of the mode group reaches 10-3 magnitude, limit loss is low, a nonlinear coefficient is small, and dispersion is low.

Description

technical field [0001] The invention belongs to the field of communication, and in particular relates to a photonic crystal fiber. Background technique [0002] In 1996, J.C.Knight et al first reported Photonic Crystal Fibers (PCF), which are superior to traditional optical fibers in terms of loss, dispersion and nonlinearity, and thus have attracted more and more attention. [0003] Orbital Angular Momentum (OAM) is an important parameter of light discovered in recent years. Light with different "twisted" forms of orbital angular momentum does not interfere with each other and can be continuously added. This greatly expands the transmission capacity of light. [0004] For optical fibers that transmit OAM modes, more modes mean packing more channels on a single frequency, significantly increasing the amount of information transmission. In order to support the stable transmission of OAM modes in the fiber, the fiber must have a high effective refractive index difference to...

AI Technical Summary

Problems solved by technology

Many optical fibers with special structures have been proposed to support the transmission of OAM modes, but the effective refractive index difference between the modes in these optical fibers is always within 10 -4 order of magnitude and cannot be significantly improved

Since the effective refractive index difference between modes cannot be improved, even and odd eigenmode shifts, birefringence and polarization mode dispersion may occur during OAM mode transmission, which affects the mode purity and causes coupling or crosstalk between modes

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