Accession Number : AD0672358

Title :   INVESTIGATION OF BRILLOUIN SCATTERING PHENOMENA AND APPLICATIONS.

Descriptive Note : Final rept. 15 Jun 67-14 Jun 68,

Corporate Author : SPERRY RAND RESEARCH CENTER SUDBURY MASS

Personal Author(s) : McMahon,Donald H.

Report Date : JUL 1968

Pagination or Media Count : 70

Abstract : During the initial six months of the contract we: (1) measured the longitudinal and shear wave attenuation of sound propagating along the c axis in crystals of LiNbO3 and LiTaO3; (2) observed acoustic second harmonic generation in LiNbO3 for both shear and longitudinal waves propagating along the c axis; (3) developed the theory of second harmonic generation to the point where the technique can be used to determine values of the third order elastic constants; (4) measured the necessary elasto-optic coefficients in LiNbO3 (P sub 13 and P sub 24); and (5) used the theory of second harmonic generation and the observed data to calculate experimental values for the third order elastic constants C sub 333 and C sub 444. During the final six months of the contract we: (1) developed the theory of acoustic second harmonic generation in piezoelectric crystals; (2) developed the mathematical analysis for determining the relative efficiency of optical Bragg diffraction as a function of interaction geometry; (3) developed the wetted mercury contract for increasing the intensity of acoustic waves; and (4) measured the acoustic attenuation of a axis longitudinal and shear waves in LiNbO3. (Author)

Descriptors :   (*CRYSTAL LATTICES, ULTRASONIC RADIATION), (*ULTRASONIC RADIATION, PROPAGATION), SOLIDS, MECHANICAL WAVES, PIEZOELECTRIC CRYSTALS, LITHIUM COMPOUNDS, NIOBATES, GARNET, ELASTIC PROPERTIES

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE