This work presents the analysis of the Lorentz light beam at a planar dielectric interface using accelerated beam propagation method (BPM). the FFT-BPM is implemented on a graphical processing unit (GPU) platform using CUDA-C program to decrease the execution time significantly. In this study, the interference between the incident and reflected beams is reported. Additionally, the angular spread of the refracted beam in the rare medium and its direction of propagation are considered. The non-specular shifts are also calculated using the FFT-BPM at sharp critical angle which is very difficult to examine using analytical methods.

When Gaussian light beam is incident on a dielectric interface, it shifts from geometric optics predictions. These shifts with planar or corrugated interfaces are known as non specular shifts which have been investigated by many researchers from the beginning of the last century till now. Further, many applications based on these shifts have very interesting practical implementations.

This work presents accurate modeling of super-Gaussian field on a step discontinues dielectric interface. The propagation of super-Gaussian field is very difficult to be solved analytically. However, in this analysis we present for the first time to the best of our knowledge the super-Gaussian field with oblique incidence at critical angle on a planar dielectric interface using fast Fourier transform based beam propagation method (FFT-BPM). The lateral field shift is also investigated

This work presents the analysis of the Gaussian light beam at a planar dielectric interface using BPM. The obtained results are in accordance with the theory of the non-specular phenomena of the electromagnetic field interaction at the same situation. Additionally, they are in a good agreement with theoretical predictions and significant improvement over the previously published results is achieved