Photonic crystal fiber capable of transmitting 22 photon angular momentum modes

Abstract

The invention discloses a photonic crystal fiber capable of transmitting 22 photon angular momentum modes. The photonic crystal fiber comprises a center fiber core, an annular high refractive index layer and an annular cladding, wherein the fiber core is a large air hole; the annular cladding comprises a cladding I, a cladding II, a cladding III and a cladding IV; the cladding I is composed of 36 square air holes in a circular uniform arrangement manner, and an included angle between every two adjacent square air holes relative to the center of a circle of a cross section of the optical fiber is 10 degrees; the cladding II is composed of 30 circular air holes in a circular uniform arrangement manner, and an included angle between every two adjacent square air holes relative to the center of a circle of the cross section of the optical fiber is 12 degrees; the cladding III is composed of 36 circular air holes in a circular uniform arrangement manner, and an included angle between every two adjacent square air holes relative to the center of a circle of the cross section of the optial fiber is 10 degrees; and the cladding IV is composed of 40 circular air holes in a circular uniform arrangement manner. According to the photonic crystal fiber disclosed by the invention, the quantity of OAM (Orbital Angular Momentum) modes supported by a waveband of 1500-1600nm reaches 22, crosstalk among the various modes is less, confinement loss of most of the modes is low (10<7>dB / m), and the photonic crystal fiber is small in dispersion and low in nonlinear coefficient.

Description

technical field [0001] The invention relates to the technical field of optical communication, in particular to a photonic crystal fiber capable of transmitting 22 photon angular momentum modes. Background technique [0002] Photonic crystal fiber (PCF) is a new research field emerging on the basis of modern optical fiber technology. Because the two-dimensional photonic crystal structure in its cladding can be flexibly designed, it has many excellent optical properties, such as no cut-off single Mode transmission, adjustable dispersion, high birefringence, large mode field area and high nonlinearity, etc. Therefore, the research of PCF has always been a hot spot for scientists in the fields of optical communication and optoelectronics. Photon orbital angular momentum (OAM, Orbital angular momentum) theoretically has an infinite number of orthogonal basis of different quantum states, so it can provide a new multiplexing mechanism. The OAM transmission fiber based on photonic ...

AI Technical Summary

Problems solved by technology

Free-space optical communication based on photon orbital angular momentum can already achieve ultra-high-speed data transmission above 2.56Tbit / s, but it is seriously affected by atmospheric turbulence and the transmission distance is relatively short

Research on optical fiber communication based on OAM is still less, because traditional optical fibers cannot transmit OAM, researchers have designed ring optical fibers that can be used to transmit OAM, and recently researchers have proposed that photonic crystal fibers can transmit OAM

However, due to the hexagonal symmetric structure of the traditional hexagonal photonic crystal fiber, there are only two transmitted OAM modes, and the loss is large

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