Optical Properties of Material for the Infrared.
Abstract
The piezobirefringence of calcium fluoride, barium fluoride, strontium fluoride, gallium arsenide, and cadmium fluoride has been measured in the infrared over the wavelength range 3.5 to 11 micrometers. A large dispersion was found in the coefficients of the fluorides; moreover, some of the coefficients were observed to reverse sign. The data for GaAs showed a small yet significant dispersion. The data for the alkaline-earth fluorides were fitted to a three parameter strain-dependent oscillator representation of the infrared-active transverse-optic (TO) phonon; the predominant contribution to the dispersion comes from the strain-induced TO phonon splitting; estimates were made to the strain-induced oscillator strength anisotropy. The GaAs data were fitted to the same model but with only two free parameters; here the predominant contribution to the dispersion came from the estimated strain-induced oscillator strength anisotropy of the TO phonon; the experimental data agree fairly well with the theory of Humphreys and Maradudin. The absolute piezo-optic constants have also been obtained at discrete laser wavelengths for the fluorides. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1982
- Accession Number
- ADA115973
Entities
People
- Albert R. Feldman
Organizations
- National Institute of Standards and Technology