Photonic crystal superprism based on negative refraction

We investigate the improvement of resolution in a photonic crystal superprism by utilizing negative refraction. The strong dispersion of the photonic crystal superprism, which is required for resolving different frequencies, results in a poor focusing of the beam, in general. We consider a hybrid-type photonic crystal structure, which combines high dispersion with negative refraction, and show that the focusing and the resolution of frequencies can be improved. We confirm this by performing finite-difference time-domain (FDTD) simulations for the photonic crystal superprism at telecommunication wavelengths.