Bends and splitters for self-collimated beams in two-dimensional triangular lattice photonic crystals

By introducing a line defect and a V-shaped defect into two-dimensional triangular lattice photonic crystals, a 60 deg beam bend, a Y-shaped beam slitter, and a one-to-three beam splitter are designed based on the self-collimation effect of photonic crystals (PCs). By analyzing the equi-frequency contours calculated with the plane wave expansion method, the frequency for self-collimation in the PC is determined. By using the finite-difference time-domain method, the beam bending efficiency and splitting ratios of the device as a function of the defect radius are calculated. These results are confirmed by computational simulations that provide field distributions of light propagating in the structures. The designed beam bend and splitters offer more choices for beam control in the design of photonic integrated circuits. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3651796]