Studies of Surface Films by Reflection of Polarized Light. I. A More Rigorous Algebraic Method for Computing Results

摘要

Planehyphen;polarized light is in general elliptically polarized by reflection. Since the molecules in a very thin surface layer are those chiefly concerned in the process of reflection, the ellipticity is very sensitive to the interface conditions such as the presence of thin films. Since light changes phase 360deg; in a single wavehyphen;length, determination of phase changes to within a few minutes of arc should allow film thickness measurements to the nearest angstrom unit. The method has been used for many years to treat problems of wide variety. The instruments and techniques employed have, on the whole, been adequate, but the interpretation of results has often been more or less unsatisfactory. The algebraic relationship between instrument readings and film constants is not exactly known. Reasonably precise graphical solution is tedious. Algebraic solutions have been preferred by most workers.This paper reports an algebraic method containing fewer approximations than used hitherto and compares results with values found by two prior methods. Drude's original equations give results in rather poor agreement with those of the more precise equations developed in this paper. Results obtained with the equations of Tronstad, on the other hand, agree fairly well in a favorable case.