A precise method for determining the principal angle of incidence and the optical constants of metals

Abstract

It is shown that, in the principal angle method for determining the optical constants of copper, an inflection point occurs in the relation between the angle of incidence, , and the orientation of the major axis of the elliptical state reflected from the metallic surface. This inflection point defines the principal angle of incidence, . In our treatment, the optical system for determining excludes the presence of a quarterwave plate. This has the advantage of avoiding errors in the value of arising from the possible deviation of the plate retardance from at the working wavelength. The principal azimuthal angle is then determined and the optical constants of a copper film at are presented. The effect of using an inexact quarterwave plate on the optical constants is discussed.