A photonic crystal fiber capable of transmitting multiple oam modes

Abstract

The invention discloses a novel photonic crystal fiber capable of transmitting a plurality of OAM (orbital angular momentum) modes. The novel photonic crystal fiber comprises a central fiber core, an annular high-refraction-index layer, a first coating layer, a second coating layer, a third coating layer and a fourth coating layer, wherein the central fiber core utilizes round air holes, and the central fiber core is covered by the annular high-refraction-index layer; the first coating layer is composed of 36 square air holes, and a rotation angle of adjacent air holes around the circle center is theta 1; the second coating layer is composed of 40 square air holes, and a rotation angle of adjacent air holes around the circle center is theta 2; the third coating layer is composed of 45 square air holes, and a rotation angle of adjacent air holes around the circle center is theta 3; the fourth coating layer is composed of 50 square air holes, and a rotation angle of adjacent air holes around the circle center is theta 4; a substrate material of each coating layer is quartz, the square air holes of all the coating layers are the same in size, the distances between the adjacent coating layers are the same, and the coating layers are symmetrically distributed in a round shape around the central fiber core. The novel photonic crystal fiber can support as many as 58 OAM modes, can transmit a plurality of HE and EH modes and can remarkably improve optical communication capacity.

Description

technical field [0001] The invention relates to a photonic crystal fiber capable of transmitting multiple OAM modes, and belongs to the technical field of photonic crystal fiber sensing. 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 crystal...

AI Technical Summary

Problems solved by technology

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, provide a photonic crystal fiber that can transmit multiple OAM modes, and solve the problem that the traditional hexagonal photonic crystal fiber has only two OAM modes for transmission due to its hexagonal symmetric structure. The core of the photonic crystal fiber is designed as a circular air hole, and the cladding is a square air hole with a ring-shaped symmetrical structure around the core. This structure makes the ring-shaped OAM transmission area and the OAM mode The annular shape of the light field closely matches, thus significantly increasing the number of transmitted OAM modes

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