Thin films

Abstract

Abstract Thin-film structures provide an important technology for making optical components with a desired surface reflectivity, either highly reflecting for such applications as laser mirrors, or minimally reflecting for the surfaces of a lens. The physics of operation and design is, of course, that of interference. There are also very insightful links with the transmission lines of §1.8. Consider Fig. 6.1, which is a miniature version of Fig. 6.4 on p. 137. A stack consisting of several thin layers of transparent dielectric has been deposited on a glass substrate. Light is incident from the left; some is reflected, some is transmitted. Within each of the thin layers there will be two waves, one travelling to the right, one travelling to the left. The amplitudes of all these waves are determined physically by Maxwell’s electromagnetic equations, and in particular by the boundary conditions: Etangential and Htangential are continuous.