Optics and Photonics Society of Iran

One of the effective methods to reduce the reflection is surface structuring (such as moth-eye structures). There are different techniques for designing structures, one of them is the use of the photonic crystals. In this way, a single anti-reflection layer can be designed with controllable structure. This layer reduces the reflection in both polarization, and large range of wavelength and incident angles. In this study, with the finite difference time domain (FDTD) method a single anti-reflection layer on silicon substrate by two-dimensional photonic crystals in a spectral range of 3-5 μm with an average reflection about 1% and transmission about 99% was simulated. This silicon anti-reflection layer is used in many optical and industrial systems, especially in the range of 3-5 μm.