Abstract

When single impurity ions go into solid solution in alkali halide crystals, very narrow absorption bands appear in the infrared spectra of these materials. These narrow bands arise from the isolation of the individual impurity ions in the crystal lattice. Such bands have a bandwidth of 2 to 6 cm⁻¹ at room temperature and 0.5 to 2.0 cm⁻¹ at liquid nitrogen temperature. The frequency of the band shifts 2 to 4 cm⁻¹ higher at liquid nitrogen temperature.

Nature of Luminescent Centers in Alkali Halide and Zinc Sulfide Phosphors*

Ferd E. Williams
J. Opt. Soc. Am. 47(10) 869-876 (1957)

Nanosecond photography at 10.6 μm using silver halide film

G. R. Mitchel, B. Grek, T. W. Johnston, F. Martin, and H. Pépin
Appl. Opt. 18(14) 2422-2426 (1979)

Optical properties and quantum efficiency of thin-film alkali halides in the far ultraviolet

Juan I. Larruquert, José A. Méndez, José A. Aznárez, Anton S. Tremsin, and Oswald H. W. Siegmund
Appl. Opt. 41(13) 2532-2540 (2002)

Infrared alkali halide fibers

James A. Harrington
Appl. Opt. 27(15) 3097-3101 (1988)

Absorption and Fluorescence Spectra of Eu²⁺ in Alkali Halide Crystals

R. Reisfeld and A. Glasner
J. Opt. Soc. Am. 54(3) 331-333 (1964)