A small-displacement sensor using total internal reflection theory and surface plasmon resonance technology for heterodyne interferometry

Sensors (Basel). 2009;9(4):2498-510. doi: 10.3390/s90402498. Epub 2009 Apr 14.

Abstract

A small-displacement sensor based on total-internal reflection theory and surface plasmon resonance technology is proposed for use in heterodyne interferometry. A small displacement can be obtained simply by measuring the variation in phase difference between s- and p-polarization states with the small-displacement sensor. The theoretical displacement resolution of the small-displacement sensor can reach 0.45 nm. The sensor has some additional advantages, e.g., a simple optical setup, high resolution, high sensitivity and rapid measurement. Its feasibility is also demonstrated.

Keywords: Total internal reflection (TIR); heterodyne interferometry (HI); small-displacement sensor; surface plasmon resonance (SPR).