Analysis of proposed PCF with square air hole for revolutionary high birefringence and nonlinearity

Abstract A novel square shaped air hole based photonic crystal fiber (PCF) is proposed with three symmetrical rectangular slots in the core region. A highly nonlinear material Gallium phosphide (GaP) is doped in the middle rectangular slot to achieve high nonlinearity and birefringence as well. Finite element method (FEM) is used for numerical investigation of the structure. Different optical parameters of the proposed PCF are calculated by varying its geometrical parameters. The optical parameters are optimized for the core pitch ( Λ C ) value between the rectangular slots as 0.18 µm. From simulation results, it can be concluded that an ultra-high nonlinear coefficient and birefringence values of 0.645 × 105 W-1 km-1 and 0.385 are achieved along with very low confinement loss and effective area of 2.10 × 10-08 dB/m and 4.18 × 10-13 m2, respectively at the centre of communication wavelength 1.55 µm. The core power fraction (CPF) is also found high as 98.056195% with extremely low effective material loss (EML) of 0.018 cm-1. Moreover, scattering loss, beat length, numerical aperture (NA), V-parameter and spot size have also been calculated. Therefore, the proposed PCF can be effectively used in single mode polarization splitter, polarization maintaining fiber, solitons generator, four wave mixer, optical signal processing, bio-medical imaging and also in sensing applications.