SPECKLE CORRELATIONS IN THE LIGHT SCATTERED BY A DIELECTRIC FILM WITHA ROUGH-SURFACE - GUIDED-WAVE EFFECTS

Diagrammatic perturbation theory is used to compute the angular intens ity correlation function q,k\q',k')=[[I(q\k)-[I(q\k)]][I(q'\k')-[I(q'\ k')]] for s-polarized light scattered from a dielectric film on a perf ectly conducting substrate. The scattering system supports two or more guided waves. The illuminated surface of the film is a weakly rough, one-dimensional random surface, I(q\k) is the squared modulus of the s cattering matrix for the system, and q,q' and k,k' are the projections on the mean scattering surface of the wave vectors of the scattered a nd incident light, respectively. Contributions to C include (a) short- range memory effect and time-reversed memory effect terms associated w ith the resonant excitation of the guided waves in the film, C-(1); (b ) an additional short-range term of comparable magnitude C-(10); (c) a long-range term C-(2); (d) an infinite-range term C-(3); and (e) a te rm C-(1.5) that, along with C-(2), displays peaks associated with the excitation of guided waves. In contrast with the results obtained in t he scattering of light from the random surface of a semi-infinite medi um, interesting features arise in the speckle correlators in the prese nt system due to the existence of the guided waves, such as various sa tellite peaks and a large multiplicity of resonant features. Both C-(1 ) and C-(2) exhibit additional peaks whose positions depend on the dif ference between the wave numbers of two guided waves (the most interes ting case of peaks arising from guided waves), whereas C-(1.5) exhibit s additional peaks whose positions depend only on the wave numbers of the guided waves taken individually.