Determining optical properties of thin films by modified attenuated total reflection with a charge coupled device

Thin films of silver produced by vacuum deposition deteriorate and tarnish when exposed to the atmosphere. This aging is due to the gradual buildup of a layer of Ag2S. When the silver layer is the plasma in an attenuated total reflection (ATR) configured waveguide the buildup of this extra layer can be observed as a shift in the angle of the resonance‐type reflection minimum. Here a modified ATR configuration which utilizes a charge coupled device has been used for accurate measurement of the angle shift of the resonance minimum.