Refractive properties of barium fluoride are discussed. The refractive index, <i>n</i>, was determined at 25°C for 46 measured wavelengths from 0.2652 µ in the ultraviolet to 10.346 in the infrared. The dispersion equation [equation] where λ is expressed in microns was found to fit the measured values with an average absolute residual of l.9×10<sup>-5</sup>. A tentative average thermal coefficient of index <i>dn</i>/<i>dt</i> for the measured spectral range is -12×10<sup>-6</sup>/°C. Dispersive quantities which indicate the expected relative dispersion, chromatic aberration, and the effect of index on resolution are graphically presented. A review of transmittance data from the literature is also presented.
IRVING H. MALITSON, "Refractive Properties of Barium Fluoride," J. Opt. Soc. Am. 54, 628-630 (1964)