Abstract

Investigations have been undertaken of the optical properties of artificial sapphire in the far infrared, utilizing the channel spectrum. The instrument used is a large interferometer designed for application in the far infrared. The interferograms and spectra show that sapphire is birefringent in the far infrared, with n_ord=3.14±4% and n_ext=3.61±4%, in the region 20 to 60 cm⁻¹. Sapphire is found to be highly transparent from 10 to 40 cm⁻¹, with the transmission dropping to zero near 90 cm⁻¹.

© 1961 Optical Society of America

Far-Infrared Properties of Quartz and Sapphire

S. Roberts and D. D. Coon
J. Opt. Soc. Am. 52(9) 1023-1029 (1962)

Absorptance of Gold in the Far Infrared*

Louis Harris and Peter Fowler
J. Opt. Soc. Am. 51(2) 164-167 (1961)

Transmission Properties of Optical Fibers*†

Robert J. Potter
J. Opt. Soc. Am. 51(10) 1079-1089 (1961)

Measurement of the Optical Constants of Crystal Quartz in the Far Infrared with the Asymmetric Fourier-Transform Method*

Edgar E. Russell and Ely E. Bell
J. Opt. Soc. Am. 57(3) 341-348 (1967)

Apparatus for the Measurement of Vacuum Ultraviolet Optical Properties of Freshly Evaporated Films before Exposure to Air

R. P. Madden and L. R. Canfield
J. Opt. Soc. Am. 51(8) 838-845 (1961)