Nanostructured, sub-wavelength anti-reflection layers (NALs) have attracted much attention as a new generation of anti-reflection surfaces. Among different designs, sub-wavelength periodic nanostructures are capable of enhancing transmission of coherent light through an interface without inducing scattering. In this work, we have explored a new profile for periodic NALs capable of transmitting IR light with higher efficiency compared to NALs based on a parabolic profile. To achieve high transmission and low diffraction, the profile and pitch of the nanostructured NALs are calculated using a combination of a multi-layer modeling and Rigorous Coupled Wave (RCWA) analysis.available materials with desired refractive indexes. Also, the mismatch between the thermal expansion coefficients of different layers, introduces residual stresses under high power illumination (this is a serious limitation for mechanical stability [6], and for applications like high power laser transmission particularly in the infrared where thicker layers are required) [7] [8].Nanostructured ARC layers (NALs [9]) on the other hand, work by a gradual, adiabatic change of effective refractive index from that of the incidence medium (air) to that of the bulk material (silicon in our case). These structures are also referred as moth-eye structures [10] due to their resemblance to the surface of a moth's eye [11]. In this paper, we will refer to nanostructures designed for re-