Rigorous Optical Modeling of Elliptical Photonic Nanowires

We analyze the optical properties including chromatic dispersion, birefringence, and nonlinear coefficient dependence on the ellipticity of photonic nanowires. We propose a linear approximation to determine the equivalent-circular photonic nanowire exhibiting similar optical characteristics with the elliptical nanowire. We find strong birefringence up to the order of 10^-2 in elliptical photonic nanowires that could be very attractive for optical fiber sensors and stable combs. We also investigate the effect of the ellipticity on the supercontinuum generation which is found to be detrimental to the spectral broadening.