Grazing angle enhanced backscattering from a dielectric film on a reflecting metal substrate

We have recently observed several features from a randomly rough dielectric film on a reflecting metal substrate including a change in the spectrum of light at the satellite peaks, the high-order correlation, and enhanced backscattering from the grazing angle. In this paper, we focus on the enhanced backscattering phenomena. The backscattering signal at small grazing angles is very important for vehicle re-entrance and subsurface radar sensing applications. Recently, we performed an experimental study of far-field scattering at small grazing angles, espe- cially enhanced backscattering at grazing angles. For a randomly weak, rough dielectric film on a reflecting metal substrate, a much larger en- hanced backscattering peak is measured. Experimental results are com- pared with theoretical predictions based on a two-scale surface rough- ness scattering model.