
Accession Number : AD0689395
Title : HARMONIC GENERATION OF MICROWAVE PHONONS.
Descriptive Note : Physical sciences research papers no. 369,
Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS
Personal Author(s) : Carr,Paul H.
Report Date : FEB 1969
Pagination or Media Count : 107
Abstract : Harmonic generation due to the phononphonon interaction and harmonic generation in nonpiezoelectric dielectrics produced by the radiation pressure of a microwave electric field was investigated. Harmonic generation due to the phononphonon interaction was measured by detecting the 9GHz secondharmonic component of acoustic waves, whose fundamental was generated by the piezoelectric effect in a 4.5GHz reentrant cavity, and was treated theoretically by obtaining perturbation solutions for both the classical nonlinear wave equation and the quantummechanical phononphonon interaction in which two collinear phonons collide to create a third phonon. The thirdorder elastic coefficients c sub 111 and c sub 333 have been measured for quartz, sapphire, and MgO. The second harmonic of longitudinal waves in MgO was observed to be of the same magnitude as the fundamental for an acoustic power of 100 mW/sq cm (strain 0.000001). Harmonic generation due to radiation pressure was measured by detecting the 9GHz acoustic waves harmonically generated at the end surface of a nonpiezoelectric rod placed in the electric field of a 4.5GHz cavity. The radiation pressure of Maxwell  Faraday stress was computed from the measured value of the electric field and used to predict the acoustic power generated. A new perturbation method was developed for measuring this electric field, which is as large as 0.00001 V/cm. (Author)
Descriptors : (*HARMONIC GENERATORS, MICROWAVE FREQUENCY), (*PHONONS, INTERACTIONS), PIEZOELECTRIC CRYSTALS, PERTURBATION THEORY, MAGNESIUM OXIDES, SAPPHIRE, QUARTZ, THESES
Subject Categories : Solid State Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE