Design and Analysis of Self-Collimation-Based Photonic Crystal Beam Splitter

We present a self-collimation-based beam splitter in a two-dimensional photonic crystal (2D-PC) by introducing defects near the termination. From the equi-frequency contour (EFC) calculations and the finite-difference time-domain (FDTD) simulations, we show that the defects can give rise to the splitting of self-collimated beams in 2D-PCs and the directivity of the deflected beam can be improved by the defect along the PC surface. In order to get different kinds of beam splitters, including the Y-shaped, one-to-three, one-to-four structures, and so on, we only need to modify the structure of the output surface (along X-M direction). The proposed splitter may have practical applications in integrated photonic circuits.