Tunable dispersion properties of liquid crystal infiltrated into a two-dimensional photonic crystal

Tunable dispersion properties of liquid crystal (LC) infiltrated into a two-dimensional silicon photonic crystal (PC) are presented. For the analysis of refraction tuning, polarization splitting and superprism effect, we make use of the variations of the dispersion curves as a function of the orientation of the optic axis of the LC. In particular, we show that the light propagation angle in the PC becomes continuously tunable by reorienting the optic axis of the LC; at a certain incident angle an extreme sensitivity of the propagation angle as a function of the orientation of the optic axis of the LC occurs. Moreover, the splitting of the transverse magnetic and transverse electric polarizations of light is substantially larger than the splitting in a conventional bulk anisotropic medium. This splitting angle can also be well controlled by adjusting the optic axis orientation of the LC. Furthermore, the variation of optic axis orientation also modifies the sharp corners of the dispersion curve, which in turn gives an excellent control of the superprism effect in the PC.