Diffraction Grating Characterization Via the Excitation of Surface Plasmons

Abstract

A diffraction grating has been manufactured in silica using interferometry and then replicated into perspex. Both grating profiles have then been characterized by fitting theory to experimentally obtained surface plasmon resonances excited on the grating surfaces after they had been coated with silver. The groove profile in the silica grating is distorted from purely sinusoidal. This distortion is very well characterized using the second-order surface plasmon and is described in this study a simple one-parameter model. The validity of the model is confirmed by similar examination of the surface plasmon resonances from the replica which is found to have the almost exactly the opposite distortion.