Effect of core infiltration in the birefringence of Photonic Crystal Fiber

Abstract

The effect of core infiltration in the birefringence of Photonic Crystal Fiber (PCF) is investigated. An elliptical soft glass rod infiltration is introduced in the core region of the fiber as it provides greater refractive index contrast between the core and the cladding. This modification also creates asymmetry in the core of the fiber which results in a resilient birefringence. Four structures (Hexagonal, Octagonal, Decagonal and Elliptical) are investigated and a comparative study is made to observe the change in birefringence due to the infiltration. It is observed that, by introducing this infiltration the birefringence is improved up to the order of 10−1. The birefringence is increased 4.82 χ 106 times in the hexagonal PCF, 5.38 χ 105 times in octagonal PCF, 546 times in decagonal PCF and about 8 times in the elliptical PCF at operating wavelength due to the core infiltration. The numerical investigation of the structure is conducted using full vector finite element method. The fabrication imperfection possibility is considered by analyzing ±2% tolerance in fiber dimension.