CaSTL Seminar with Alex Maradudin

Date: 
Thursday, April 9, 2015 - 01:00
Location: 
2201 Natural Sciences II
Speakers: 
Alex Maradudin, UC Irvine, Department of Physics and Astronomy
Event Title: 
Numerical studies of the scattering of light from, and its transmission through, two-dimensional randomly rough surfaces
Host: 
Ara Apkarian

Calculations of the scattering of light from, and its transmission through, two-dimensional randomly rough surfaces are computationally intensive, and are still often carried out by means of small-amplitude perturbation theory, the Kirchhoff approximation, or the small slope approximation.  However, accurate approaches to the solution of such problems are needed in a variety of contexts, and searches for such approaches are an active area of research in computational electrodynamics. In this talk I describe some recent work in which nonperturabative, purely numerical solutions of the integral equations of scattering theory are applied to such scattering and transmission problems.

 

I first present solutions of the Rayleigh equations for the scattering of p- and s- polarized light from a two-dimensional randomly rough perfectly conducting surface.  The solutions are used to calculate the reflectivity of the surface, the mean differential reflection coefficient, and the full angular distribution of the intensity of the scattered light.  These results are compared with the results of our earlier rigorous numerical solutions of the corresponding Stratton-Chu equations (Phys. Rev. A 81, 013806(1-13)(2010), and very good agreement is found.  Through such comparisons insight into the limits of validity of the Rayleigh hypothesis can be gained.

 

The transmission of polarized light through a two-dimensional randomly rough interface between two dielectric media has been much less studied, by any approach, than the scattering of light from such an interface.  We have solved numerically the reduced Rayleigh equations for the transmission of p- and s- polarized light through such an interface.  The solutions are used to calculate the transmissivity of the interface, the mean differential transmission coefficient, and the full angular distribution of the intensity of the transmitted light.

 

Analogous results for the scattering of p- and s- polarized light from the two-dimensional randomly rough surface of a metal will also be presented, and compared with experimental results.

 

The results obtained can be used as benchmarks against which the results of approximate, perturbative or numerical, calculations of the scattering of polarized light from, and its transmission through, two–dimensional randomly rough surfaces can be compared.