Design for directional emitter based on self-collimation photonic crystal by adding two-layer dielectric rods

We propose a novel directional emitter for achieving highly efficient beaming of self-collimated light from two-dimensional photonic crystal (PC). The structure is composed of a two-dimensional (2D) photonic crystal and two-layer dielectric rods. The finite-difference time-domain (FDTD) simulations show that the emission properties are sensitive to the distance between photonic crystal and two-layer dielectric rods. By adjusting the relative position of the two-layer dielectric rods, highly efficient beaming emission can be realized.