Refractive Index Measurements of CaF2 Single Crystal and Melt by Ellipsometry
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Abstract:
Refractive indices of CaF2 have been determined by ellipsometry and factors determining the temperature dependence have been discussed. Measurements were made on CaF2 single crystal and melt in dehydrated He atmosphere in the temperature ranges room temperature-1050 K and 1600-1800 K, respectively. The standard deviation in the measured refractive indices was within ± 0.001. The refractive indices obtained have been approximated to the following equations: Single crystal: n = n298 – 1.541×10(T – 298) 298 – 1050 K Melt: n = n1600 – 4.667×10 (T – 1600) 1600 – 1800 K where n298 = 1.429 and n1600 = 1.409. It is likely that the temperature coefficients are determined predominantly by those of the densities.Keywords:
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