一种可传输轨道角动量的螺旋光子晶体光纤

A Spiral Photonic Crystal Fiber Capable of Transmitting Orbital Angular Momentum

摘要:

设计了一种基于阿基米德螺线的新型螺旋光子晶体光纤,该光纤以二氧化硅为基底材料,包层由24个螺旋臂组成,每个螺旋臂包含11个小空气孔,纤芯设有大空气孔,包层与纤芯中间的环形区域用于传输轨道角动量模式。该结构在1300~1800nm波段上可支持22种轨道角动量模式稳定传输,在1550nm波长下,有效折射率差最高可达 2.89×10-3,色散系数最低可达 66.4ps/(nm·km),非线性系数最低可达2.17W-1·km-1,且1500~1600nm 波段上的色散值变化均小于15.15ps/(nm·km)。此螺旋光子晶体光纤不仅结构简单,且具有低非线性、色散平坦的性能,为螺旋光子晶体光纤的设计提供了思路。

Abstract:

A new type of spiral photonic crystal fiber based on Archimedes spiral is proposed, and silica is chosen as the background material. The cladding is composed of 24 spiral arms, each spiral arm contains 11 small air holes, and there is a big air hole in the center of the fiber core. The annular area between the cladding and the air-core can transmit the orbital angular momentum mode. It can support stable transmission of 22 kinds of orbital angular momentum modes over the wavelength range of 1300~1800nm. The effective refractive index difference can be up to 2.89×10-3, the lowest dispersion can reach 66.4ps/(nm·km), and the nonlinear coefficient is minimally up to 2.17W-1·km-1 at 1550nm wavelength. The dispersion variation is less than 15.15ps/(nm·km) in the wavelength range of 1500~1600nm. The spiral photonic crystal fiber is not only simple in structure, but also has low nonlinearity and flat dispersion performance, which provides an idea for the design of spiral photonic crystal fiber.