Angular dependence of roughness-assisted surface plasmon radiation: Comparison of theory and experiment

We present a calculation of the angular distribution of surface-plasmon radiation from a rough surface. The radiated fields are calculated to first order in the surface-roughness height $\delta$, and the results are compared with our earlier measurements. The present result is found to compare more favorably with experiment than a previous calculation by Kretschmann. The strength of the "backscattering" of surface plasmons from small surface features is determined and used to discuss certain features of the experimental results.