The effect of surface plasmon-polaritons on the photostimulated diffusion in light-sensitive Ag–As4Ge30S66 structures

Abstract

The effect of surface plasmon-polaritons (SPPs) excited at the interface between the profiled surface of the silver layer (in the form of a diffraction grating) and the As4Ge30S66 layer on the photostimulated diffusion of silver into chalcogenide has been studied. The gratings with the period a = 519 nm and modulation depth h/a ≈ 0.037 (where h is the grating depth) were formed on chalcogenide photoresist films by using interferential lithography and covered with the 80-nm-thick aluminum layer, 85-nm-thick silver layer, and thin As4Ge30S66 layer. Photostimulated changes in this structure were studied measuring the angular dependences of specular reflection (Rp) of p-polarized light with the wavelength 632.8 nm. It was found that as a result of exposure, “degradation” (broadening, increase in reflection at the minimum) of the minimum in the angular dependence of Rp (which is associated with the SPP resonance) occurs faster, when the samples are irradiated at the angle corresponding to SPP excitation. This observation indicates acceleration of the photostimulated diffusion process in this structure under the plasmon field action.