Abstract

The semi-metals germanium and silicon have high transparency and high refractive indices over a wide range of infrared wavelengths and are stable to normal atmospheres. Their relative indices and dispersions make achromatic combinations possible; and designs are given for axially corrected doublets of relative apertures f:2 and f:1. The optical homogeneity of the materials is discussed: compositional variations are not considered an optical hazard, but there is evidence of structural imperfections in some specimens whose effect on optical properties remains to be evaluated.

© 1951 Optical Society of America

Optical Constants of Germanium, Silicon, and Pyrite in the Infrared

Ivan Šimon
J. Opt. Soc. Am. 41(10) 730-730 (1951)

The Color Correction of an Achromatic Doublet

T. Townsend Smith
J. Opt. Soc. Am. 10(1) 39-63 (1925)

Five-Inch Molded Silver Chloride Correctors for a Kellner-Schmidt System*

J. C. Evans and T. A. King
J. Opt. Soc. Am. 41(8) 510-512 (1951)

Achromatic Doublet Lenses for Infrared Radiation

J. Strong
Appl. Opt. 10(6) 1439-1443 (1971)

The Color Correction of an Achromatic Doublet. II.

T. Townsend Smith
J. Opt. Soc. Am. 15(5) 247-256 (1927)