A new high-resolution displacement sensor based on Surface Plasmon Resonance
Year: 1996
Authors: Margheri G., Mannoni A., Quercioli F.
Autors Affiliation: Istituto Nazionale di Ottica, Largo E. Fermi 6, 50125 Firenze, Italy
Abstract: In this work we report on a novel angular and positional sensor based on the phenomenon of Attenuated Total Reflection that occurs at a metal-dielectric interface when the conditions for the excitation of a Surface Plasma Wave in Kretschmann configuration are satisfied. The reflectivity of the metallic surface exhibits a very sharp dip at an angle of incidence corresponding to the phase-matching condition for the coupling of energy from the incident beam to the resonant surface mode. The typical width of the resonance is a few mrad, thus making feasible the direct measurement of small angular movements by just detecting the intensity of the reflected light. By means of a simple optical setup this sensitivity can be exploited to build a position-sensitive detector capable of nanometric resolution. Tests have been carried out on several Ag depositions. The angular resolution obtained has been in the 0.2-0.4 arcsecs. range; the sensitivity to linear displacements has been tested monitoring the motion of piezoelectric actuators and is better than 5mu over a range of a few microns. We have verified that the proposed method does not require beams of high optical quality and permits in principle a considerable simplification over interferometric systems. Well-established technological processes might be used for its implementation, keeping its cost at a competitive level with respect to other devices ofthe same potential sensitivity.
Journal/Review: PROCEEDINGS OF SPIE
Volume: 2783 Pages from: 211 to: 220
KeyWords: Total Reflection; Surface Plasma Wave; metal-dielectric interfaceCitations: 2data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-04-21References taken from IsiWeb of Knowledge: (subscribers only)