We present the results of index of refraction and absorption coefficient measurements of high-quality optical grade sapphire over the 1850 cm-1 10000 cm-1 wave number range and temperatures from 10 K to 295 K. The refractive index is determined by a combination of room-temperature minimum-deviation prism measurements at 2950 cm-1 and temperature dependent high-resolution transmission measurements of a 1 mm thick etalon sample from the same batch of material. A Brewster-angle polarizer with an extinction ratio of <10-5 is used for polarization selection. The uncertainties in the fringe counting method are analyzed. The temperature dependence of the absorption coefficient is compared with the predictions of a multi-phonon model for sapphire.
Proceedings Title: Cryogenic Optical Systems and Instruments , Conference | 9th | Cryogenic Optical Systems and Instruments IX | SPIE
Conference Dates: July 7-11, 2002
Conference Title: Proceedings of SPIE--the International Society for Optical Engineering
Pub Type: Conferences
absorption coefficient, index of refraxtion, sapphire, thermo-optic coefficient