Efficient beaming from photonic crystal waveguides via self-collimation effect

Emission behavior of a subwavelength photonic crystal (PC) W1 waveguide covered by a self-collimation PC to the exit surface is investigated using finite-difference time-domain method. When the thickness and the relative position of the covering PC is designed appropriately, highly efficient beaming emission is obtained. The authors analyze the numerical results and attribute the beaming effect to the interference of the multiple self-collimation beams excited by the waveguide. This simple structure may find its potential applications in integrated optical circuits. (c) 2006 American Institute of Physics.