Highly birefringent nonlinear PCF for optical sensing of analytes in aqueous solutions

This paper presents a design of a nonlinear Photonic Crystal Fiber (PCF) based sensor exhibiting simultaneously high sensitivity, high birefringence and low confinement losses for liquid analyte sensing applications. We investigate the PCF sensor performance for the following analytes; Water, Ethanol and Benzyne. The impact of various design parameters of the highly nonlinear PCF on the relative sensitivity, the confinement losses and the birefringence features of the proposed PCF structure is numerically investigated by employing the full vectorial Finite Element Method (FEM). According to our FEM numerical results, a three ring nonlinear PCF based sensor is designed that simultaneously offers high birefringence of order 10-3 and high relative sensitivity at wide wavelength range.