COMPUTATION, VISUALIZATION, AND ANIMATION OF INFRARED MUELLER MATRIX-ELEMENTS BY SCATTERING FROM SURFACES THAT ARE ABSORBING AND RANDOMLY ROUGH

Computation of Mueller matrix elements by infrared scattering from randomly rough two-dimensional surfaces and results of a method for graphic display of the data are presented. A full wave electromagnetic scattering model first generates raw data elements of the 4 x 4 Mueller matrix F(theta, n(lambda), k(lambda), sigma(s2), [h2]) in beam backscattering angle (theta) ranging from normal to oblique incidence, in refractive index of the beam scatterer (n(lambda) - ik(lambda) spanning the 9 less-than-or-equal-to lambda less-than-or-equal-to 12.5 mum midinfrared band, and in mean-squared slope (sigma(s2)) and mean-squared height ([h2]) of the scattering surface. These data are next compressed into a graphics format file occupying considerably less computer storage space and mapped into color images of the Mueller elements as viewed on a high-resolution graphics terminal. The diagonal and two off-diagonal elements are animated in the lambda-theta plane according to variations in sigma(s2) and [h2]. Predicted elements for polarized IR beam energies on vibrational resonance of the surface molecules, and particularly the off-diagonal elements, show subtle properties of the scatterer as viewed in the animation sequences.