Tunable negative refraction by electro-optical control in two-dimensional photonic crystal

We analyze negative refraction in two-dimensional photonic crystals that are made from electro-optical active materials. Application of an electric field to the photonic crystal changes the dielectric constant of the material and consequently modifies the photonic band and dispersion properties. We have investigated focusing properties of the photonic crystal slab lens at different frequencies within the first two bands and under various magnitudes of electric field. The simulation results reveal that one can dynamically tune negative refraction by means of index-tunable photonic crystals.