Abstract
The optical constants and reflectance and transmittance of evaporated rhodium films were determined in the visible. The evaporations were performed in an ion-titanium pumped system at pressures of less than 10−6 torr. Films of various thicknesses were deposited onto glass and fused-silica substrates at 40 and 300 °C. Their optical constants were determined with opaque coatings by an ellipsometric technique, and by reflectance measurements made at various angles of incidence, and with semitransparent films by reflectance, transmittance, and thickness measurements. The results obtained with these three techniques agreed well within the accuracy of measurements. At all wavelengths, both n and k and the reflectance increased with increasing substrate temperature. The transmittance of semitransparent rhodium films of various thicknesses was found to be not as constant throughout the visible region as previously reported. The rhodium mirror coatings were made to adhere to glass and fused silica, by use of a 20-Å-thick inner layer of evaporated Nichrome. Pairs of dielectric surface films with alternately low and high indices of refraction were used to enhance the visible reflectance of rhodium mirrors. They consisted of SiO2 + TiO2 and SiO2 + CeO2. Rhodium mirrors with and without dielectric surface films showed no damage or change in reflectance after 1 h of boiling in salt water and 10 h of immersion in 10% NaOH and 10% HCl acid.
© 1973 Optical Society of America
Full Article | PDF ArticleMore Like This
G. Hass and J. E. Waylonis
J. Opt. Soc. Am. 51(7) 719-722 (1961)
J. T. Cox, G. Hass, J. B. Ramsey, and W. R. Hunter
J. Opt. Soc. Am. 63(4) 435-438 (1973)
J. Thomas Cox, G. Hass, and W. R. Hunter
J. Opt. Soc. Am. 61(3) 360-364 (1971)