Abstract

We consider thin film light guides consisting of a transparent film of high refractive index deposited on a substrate of lower index. The propagation of light in such a two-dimensional transmission medium can be described within the limits of geometrical optics by an effective index of refraction N. Its value depends on the film thickness. Therefore, a light beam in the thin film guide is refracted or totally reflected at a step of film thickness. We discuss these phenomena (Snell’s law) and demonstrate them experimentally, using ZnS films on glass as guides. As applications, we show a thin film prism and thin film lenses for guided light beams. By properly choosing the film thicknesses at both sides of the step, one can obtain an unusually large positive or negative wavelength dispersion of the refraction or, if desired, achromatic refraction.

© 1971 Optical Society of America

Light Waves in Thin Films and Integrated Optics

P. K. Tien
Appl. Opt. 10(11) 2395-2413 (1971)

Theory of Prism–Film Coupler and Thin-Film Light Guides

P. K. Tien and R. Ulrich
J. Opt. Soc. Am. 60(10) 1325-1337 (1970)

Optical Guided-Wave Focusing and Diffraction*

R. Shubert and J. H. Harris
J. Opt. Soc. Am. 61(2) 154-161 (1971)

Optical Propagation in Sheet and Pattern Generated Films of Ta₂O₅

D. H. Hensler, J. D. Cuthbert, R. J. Martin, and P. K. Tien
Appl. Opt. 10(5) 1037-1042 (1971)

Guided-wave optical thin-film Luneburg lenses: fabrication technique and properties

S. K. Yao, D. B. Anderson, R. R. August, B. R. Youmans, and C. M. Oania
Appl. Opt. 18(24) 4067-4079 (1979)