Dual-cladding high-birefringence and high-nonlinearity photonic crystal fiber with As2S3 core

A novel dual-cladding photonic crystal fiber (PCF) with elliptical As2S3 core has been proposed to obtain high-birefringence and high-nonlinearity in PCFs. As2S3 has a high refractive index and a high nonlinear refractive index, as a result, it has a desired application on strengthening birefringence and nonlinearity. Then outer cladding of the PCF contains a hexagonal array of circular air holes. A circular array of circular air holes is introduced near the core as the inner cladding. We find that inner cladding could heighten birefringence and nonlinearity obviously. The simulation results show that the birefringence is as high as 0.307 at a wavelength of 1550 nm, and the nonlinearities of X- and Y-polarized reach 28660 km−1 W−1 and 38080 km−1 W−1 at the same wavelength, respectively.