Experimental Determination of the Optical Constants of Metals

Abstract

The optical constants of metals given in reference tables are the so-called Drude constants, which pertain to normal incidence of light. They are generally measured by katopteric methods at angles of incidence greater than zero. It has sometimes been suspected that the values so measured are not constant but vary with the angle of incidence. This report concerns the optical constants of gold films prepared by vacuum evaporation. The results indicate that the Drude constants do not depend upon angle of incidence, and that observed variations are due to various experimental errors.