Dispersion and birefringence properties of a novel As2Se3 photonic crystal fiber nanowire

In this paper, we have characterized a mid-IR nonlinear photonic device consisting of a highly nonlinear As₂Se₃ nanowire and a novel photonic crystal structure on silica clad. The lowest optical confinement was found about 60% over the entire bandwidth for an optimum nanowire radius of 600 nm. The highest anomalous GVD obtained was about 1348 ps/nm. km with the lowest anomalous GVD bandwidth of around 2500 nm. The lowest nonlinearity obtained was on the order of 10⁴ W^-1 km^-1, which ensures that the device is ideal for mid-IR super-continuum (SC) generation. It has been found that a birefringence about 30000 times higher than that of a circular nanowire may be obtained due to only 5% deformation of the nanowire. A relationship between the peak value of birefringence and nanowire ellipticity has been obtained for a certain design parameter. Finally, supercontinuum simulation has been conducted to realize the effects of high anomalous dispersion accompanied by ultra-high nonlinearity.