Accession Number : AD0686252

Title :   APPLICATION OF THE NONUNIFORM-FIELD TREATMENT TO THE INFRARED PROPERTIES OF LiF,

Corporate Author : CANADIAN ARMAMENT RESEARCH AND DEVELOPMENT ESTABLISHMENT QUEBEC

Personal Author(s) : Beaulieu,A. J.

Report Date : 15 JUL 1968

Pagination or Media Count : 16

Abstract : The 'nonuniform-field treatment' developed earlier for infinitely thick crystals is applied to the LiF crystal. Comparison with experimental results both at 45 deg and at small angles of incidence gives good quantitative agreement only when the ratio of the longitudinal optical frequency to the transverse optical frequency is assumed to be 1.7 instead of 2.2 as predicted by the Lyddane-Sach-Teller relation. An extension of the treatment to thin films is presented and the comparison of the results with Berreman's experimental values indicates that the asymmetry and the amplitude of the features which could not be explained before can be predicted in terms of the nonuniform-field treatment, again provided the optical phonon frequency ratio is 1.7. (Author)

Descriptors :   (*LITHIUM FLUORIDES, *INFRARED SPECTRA), CRYSTALS, ELECTROMAGNETIC FIELDS, PHONONS, FILMS

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE