Optical Materials Characterization
Semi-annual technical rept. 1 Aug 1975-31 Jan 1976
NATIONAL BUREAU OF STANDARDS WASHINGTON DC INST FOR BASIC STANDARDS
Pagination or Media Count:
Refractive index and the photoelastic constants have been measured on specimens of reactive atmosphere processed RAP potassium chloride and KCl nominally doped with 1 potassium compounds iodine. The refractive indices were measured by the minimum deviation method in the wavelength range 0.25 micrometer to 15.5 micrometers. Measurements were made near 20 C and near 34 C on the RAP specimen and near 20 C on the doped specimen. Each set of experimental data was fitted to a three term Sellmeier-type dispersion equation. The temperature coefficient of index was then computed for the RAP KCl. The data for the different types of KCl were compared to each other and to earlier reported data on commercial KCl. The piezo-optical constants q sub 11, q sub 12 and q sub 44 and the elasto-optical constants p sub 11, p sub 12 and p sub 44 were obtained at 10.6 micrometers for the RAP and doped KCl. The measurements required the use of a modified Twyman-Green interferometer capable of measuring fringe shifts approximately .002 of a wave. Within experimental error the coefficients of the two materials agree. Negligible dispersion was found for q sub 11, q sub 12, p sub 11 and p sub 12 between the visible and 10.6 micrometers while a small dispersion was found for q sub 44 and p sub 44.
- Miscellaneous Materials