Strong angular dispersion using higher bands of planar silicon photonic crystals.

We present experimental evidence for strong angular dispersion in a planar photonic crystal (PC) structure by properly engineering the modes in the second PC band. We show that by using the second photonic band of a square lattice PC, angular dispersion of 4 degrees /nm can be achieved. We also show that major challenges in designing practical PC devices using second band modes can be addressed by engineering the lattice and adding input/output buffer stages designed to eliminate unwanted effects.