Photonic crystal fiber

Abstract

The invention discloses a photonic crystal fiber, which is characterized by comprising a core layer, a cladding layer and a coating layer from the inside to the outside, wherein the cross section of the fiber is circular, the core layer, the cladding layer and the coating layer are concentric, the core layer is arranged at the innermost layer of the fiber, the center of the cross section of the core layer is a circular hole, a plurality of semicircular air holes are uniformly formed in the cladding layer, the cladding layer comprises five cladding layer rings, each of the cladding layer ring is formed by sequentially connecting the semicircular air holes of the same size, the sizes of the semicircular air holes in the cladding layer rings are progressively increased in sequence from the inner ring to the outer ring, convex surfaces of the semicircular air holes in every two adjacent rows of cladding layer rings, the coating layer is arranged at the outermost layer, the core layer and the cladding layer are made of silicon dioxide crystals or silicon crystals, and the coating layer is made of acrylate or organic silicon resin. The photonic crystal fiber disclosed by the invention can transmit a plurality of orbital angular momentum modes, the effective refractivity difference of the mode group reaches 10<-3> magnitude order, the confinement loss is low, the nonlinear coefficientis small, and the chromatic 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] Orbital Angular Momentum is another important parameter of photons besides the traditional wavelength, polarization and other parameters. With the continuous improvement of technologies such as wavelength division multiplexing, time division multiplexing, and code division multiplexing in the field of optical communication, the amount of data transmitted by traditional optical fibers is close to saturation. OAM provides a A whole new degree of freedom. [0003] In the OAM optical fiber communication system, the optical fiber supporting OAM mode transmission is a key component. Photonic Crystal Fiber (PCF) has attracted widespread attention in recent years. Its cross-section has a complex refractive index distribution, and usually contains pores in different arrangements. The scale of these pores is roughly the same...

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 modes in these optical fibers is always on the order of 10-4, which 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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