Highly efficient self-collimation based waveguide for Mid-IR applications

An efficient backbone is introduced for optical integrated circuits at Mid-IR region using PbTe (n(PbTe) similar to 6) as the background material in a holetype 2D square lattice photonic crystal in this article. The proposed waveguide benefits insensitivity to the polarization and is also virtually allangle. Furthermore, it is applicable to a broad spectral width of 30 nm considering only a small compromise of 3 on the degree of selfcollimation which will not cause a significant challenge in practical integrated applications. Here, based on finite difference time domain analysis, a complete study on coupling efficiency of the introduced structure is presented. It is shown that for optimized antireflection, the structure benefits a coupling efficiency of similar to 70% for TE and TM polarizations around the central wavelength of lambda = 4.1175 mu m. In this study, a single row of holetype antireflection is used which does not affect the allangle SC property of the proposed waveguide. (C) 2016 Elsevier B.V. All rights reserved.