Surface Roughness Driven Broadband Second Harmonic Generation in Zinc Selenide slab

The effect of surface roughness on second harmonic broadband generation in the region of mid-infrared, in a reverse tapered semiconductor slab made up of Zinc Selenide (ZnSe) is described analytically in this paper using total internal reflection-quasi phase matching (TIR-QPM) technique. After taking into account for roughness and scattering due to reflection, a computer-aided simulation of ZnSe slab yielded a 3-dB bandwidth of 343.04 nm centering at 7.33 μm with a peak conversion efficiency of 1.19%. The effect of variation in crystal length, operating temperature, and tapered angle on the performance parameter has been evaluated.