Optical Determination of Thin Films on Reflecting Bases in Transparent Environments

The classical theory of metal and film optics is recapitulated and its implications in connection with various optical methods of studying films and surfaces are indicated. The experimental technique of determination of thin films in situ from the change produced in the reflection of a polarized wave is then outlined. Optical techniques are not advocated to supplant other methods of studying surfaces such as weight increment, gas absorption, electron diffraction, x-ray diffraction, and electrochemical analysis, but rather to supplement these in selected cases. In particular, the optical techniques are of value in making continuous studies of films in situ in transparent environments when conditions render the application of other methods difficult. Examples of applications are given.