Accession Number : AD0466176

Title :   STIMULATED BRILLOUIN SCATTERINGS IN ANISOTROPIC MEDIA AND OBSERVATION OF PHONONS,

Corporate Author : OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS ANTENNA LAB

Personal Author(s) : Hsu, H. ; Kavage, W.

Report Date : 15 JUN 1965

Pagination or Media Count : 13

Abstract : Stimulated Brillouin scattering belongs to the general class of parametric interactions of waves and quasi-particles such as magnons, and plasmons as well as phonons. These interactions are governed by Tien's phase matching equations corresponding to the conservation relationships of energy and momentum. For anisotropic media, the interaction can be classified into three types depending upon the scattering angle between the incident and scattered light. In this paper, the basic process of stimulated Brillouin scattering in anisotropic media is discussed. It is shown that stimulated phonons at radio frequencies can be excited and propagated at room temperature. The characteristic of these phonons in crystal quartz is discussed. The result of the investigation indicates that there is a tendency for stimulated Brillouin scatterings to be initiated near the boundaries of finite crystals due to the relatively large phonon anharmonicity at the boundary. The phonon anharmonicity appears to be the dominating factor in the nonlinearity responsible for parametric interaction in stimulated Brillouin scattering. (Author)

Descriptors :   (*LASERS, PHONONS), ANISOTROPY, EXCITATION, QUARTZ, POLARIZATION.

Distribution Statement : APPROVED FOR PUBLIC RELEASE