Highly directional emission from multi-channel photonic crystal via beam splitting

Efficient directional emission is realized by using beam splitting in multi-channel photonic crystal (PC). The periodic channels are introduced on the exit surface of a PC waveguide to create multiple light beams, whose interference leads to the directional emission. In order to improve the quality of the directional emission, coupled PC waveguides with low-loss are designed to make the incident light split into several beams. The simulation results show that the transmission efficiency is greatly enhanced by beam splitting.