Fiber-optic surface-plasmon resonance for the determination of thickness and optical constants of thin metal films

We demonstrate that the thickness and the dielectric constants of thin gold films deposited on the surface of a fiber core can be quantitatively deter mined as a single set of solutions by the simple measurement of the fiber-o ptic surface-plasmon resonance responses. This method is capable of directl y characterizing metal films with curved surfaces: this is very hard to per form by use of the conventional optical techniques of reflectometry and ell ipsometry. The theoretical errors for the experimental fiber are estimated to be within d +/- 2%, epsilon(r) +/- 1%, and epsilon(i) +/- 15%. (C) 2000 Optical Society of America. OCIS codes: 120.4530, 240.0310, 120.1880, 240.6 680, 066.2370.