Photoacoustic study of plasmon resonance absorption in a diffraction grating

Abstract
Plasmon resonance absorption in a 520-line/mm silver-coated diffraction grating was measured as a function of the angle of ruling orientation relative to the plane of photon incidence by a photoacoustic method. The experimental results of absorptance changes as a function of ruling orientation were found to be consistent with predictions from the first-order perturbation theory for roughness-induced photoabsorption. A discrepancy was found, however, between the absorptance values observed and the values calculated from the first-order theory.