New technique for measurement of refractive index and thickness of polymer thin films

Abstract

Prism coupling into optical waveguides is a Well-known technique tor determining refractive index and thickness of thin films. We show that it is not necessary to use an optical waveguide to obtain m lines and measure refractive index and thickness of thin films. It is possible to use films whose refractive index is less than that of the substrate and couple into radiation modes which contain information about the film. Although this quasi-waveguide is leaky, prism coupler measurement of the m lines provides a simple and elegant technique to determine film parameters.