THE MUELLER MATRIX FOR ROUGH-SURFACE SCATTERING USING THE KIRCHHOFF APPROXIMATION

The Kirchhoff approximation is used to find the scattered intensities and the Mueller matrix for a gaussian surface with standard deviation of height-sigma = 1.22-mu-m and correlation length-tau = 3.18-mu-m using a wavelength of lambda = 0.633-mu-m. The cases of gold (n = 0.167 + i 3.149) and dielectric (n = 1.41) surfaces are considered. Results are compared with experimental observations and are shown to give good agreement. The single and double scattered intensities are shown to be fully polarised for both cases whereas the total (single plus double) shows a strong unpolarised component for the gold case. This effect is understood by considering that the single and double scatter terms are partially coherent and at right angles to each other.