Design of Single-Polarized Single-mode Photonic Crystal Fiber Without Air Holes in the Cladding

Abstract

Abstract This study proposes a novel single-polarized single-mode (SPSM) photonic crystal fiber (PCF) without air holes in the cladding, and the silicon nitride holes and air holes in the core of the PCF are staggered. Based on the full vector finite element method, the birefringence characteristics with different hole sizes have been discussed in detail, and a SPSM-PCF is achieved through optimizing the core structure. Moreover, the extinction ratio, effective refractive index, dispersion, confinement loss and nonlinearity of the PCF are analyzed. Simulation results show that the PCF can obtain a high birefringence value of 2.142 × 10−3 , a large negative dispersion of −2750 ps/(nm · km), a low confinement loss of 1.57 × 10−7dB/m and a high nonlinear coefficient of 90.5W−1 · km−1 at the wavelength of 1.55 μm. In this paper, the proposed structure has the properties of high birefringence and high negative dispersion, which can be used in fiber laser, optical fiber sensing, dispersion compensation and other fields.