John H. Burnett, Eric C. Benck, Simon G. Kaplan, Erik Stover, Adam Phenis
Measurements of the index of refraction of a sample of high-quality, single-crystal germanium using the minimum deviation refractometry method are presented for temperatures near 22 degC and for wavelengths in the range 2 micron to 14 micron. The standard uncertainty for the measurements ranges from 1.5 x 10^-5 to 4.2 x 10^-5, generally increasing with wavelength. A Sellmeier formula fitting the data for this range is provided. Details of the custom system and procedures are presented, along with a detailed analysis of the uncertainty. These results are compared with previous measurements.