Engineering of directional emission from photonic-crystal waveguides

We analyze, by the finite-difference time-domain numerical method, different ways to enhance the directional emission from photonic-crystal waveguides through the recently predicted beaming effect. We demonstrate that the substantial enhancement of the light emission can be achieved by adjusting the input wavelength, using a positive surface corrugation, increasing the refractive index of the surface layer, and inducing a near-surface mode. (c) 2005 American Institute of Physics.