New evidences of negative refraction in photonic crystals

To verify the behavior of negative refraction in photonic crystals, we design a point source imaging system in which a point source is placed at a distance in front of photonic crystals slab. The distance is equal to the thickness of the slab. By numerical simulation based on the finite-difference time-domain (FDTD), the light beam inside the slab just focuses from one side to the other side of the slab and makes a clear image. Our result proves that negative refraction occurs inside PC for a certainty on special condition.