Superprism phenomena in planar photonic crystals

We utilize the anomalous dispersion of planar photonic crystals near the dielectric band edge to control the wavelength-dependent propagation of light. We typically observe an angular swing of up to 10/spl deg/ as the input wavelength is changed from 1290 nm to 1310 nm, which signifies an angular dispersion of 0.5 degree/nm. Such a strong angular dispersion is of the order required for wavelength-division multiplexing systems. This is the first demonstration of the "superprism" effect in a planar configuration with a small lattice.