Electromagnetic engineering of the dispersion properties of photonic crystal devices

We present a photonic-crystal (PhC) device that does not require line defects for confinement and yet can arbitrarily route light by exploiting engineered dispersion. Our proposed device is based on engineering the dispersion properties of a two-dimensional slab PhC such that the propagation of light is permitted only in certain directions. We demonstrate the application of dispersion engineering in photonic crystals for efficient waveguiding, routing, and splitting. We have experimentally demonstrated self-collimation in planar PhCs, and a new means of achieving structureless confinement of light in optical devices. The applications of these devices are far-reaching in that they allow for very high-density photonic circuits due to the lack of structural interaction as well as their ability to propagate and route optical beams in an arbitrary fashion with low loss.