Measurement of wavelength shift by using surface plasmon resonance heterodyne interferometry

Abstract

A linearly polarized light is incident on a surface plasmon resonance (SPR) apparatus at the resonant angle. the surface plasmons are excited, Small wavelength shifts will introduce phase difference variations between s- and p-polarizations of the reflected light. These phase difference variations can be measured accurately by using heterodyne interferometry. Based on these facts, a novel method for measuring small wavelength shifts is proposed. It has the advantages of both common-path interferometry and heterodyne interferometry. (C) 2002 Elsevier Science B.V. All rights reserved.