Method of Using the Reflectance Ratios of Different Angles of Incidence for the Determination of Optical Constants

A determination of the optical constants of a bulk specimen may be made by measurement of the intensity reflected from the surface of the specimen for at least three angles of incidence. None of the incidence angles needs to be equal to 90 degrees , although when one is, this can be equivalent to the case when the incident intensity is measured. The accuracy with which the optical constants may be determined depends on the choice of the three angles as well as on the accuracy of measurement of the reflected intensity. Results are presented that indicate a suitable choice of angles for unpolarized incident radiation.