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Index of refraction of germanium



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 degC 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.
Applied Optics


germanium, Ge, index of refraction, refractive index, thermo-optic coefficient, dn/dT


Burnett, J. , Benck, E. , Kaplan, S. , Stover, E. and Phenis, A. (2020), Index of refraction of germanium, Applied Optics, [online], (Accessed February 27, 2024)
Created April 27, 2020, Updated April 28, 2020