J. Phys. Colloques
Volume 42, Numéro C6, Décembre 1981International Conference on Phonon Physics
|Page(s)||C6-676 - C6-678|
J. Phys. Colloques 42 (1981) C6-676-C6-678
PARAMETRIC AMPLIFICATION OF MICROWAVE PHONONS IN SEMICONDUCTORSH.N. Spector1, 2
1 Illinois Institute of Technology, Chicago, IL, U.S.A.
2 Supported by a grant from the NSF Material Research Laboratory Program, Grant No. 76-24466.
Two different nonlinear processes involving the interactions of phonons with electrons in a semiconductor in the presence of a d.c. electric field have been theoretically investigated. The first process involves the mixing of ultrasonic waves to generate new ultrasonic waves at the sum or difference frequencies of the original waves. The mechanisms which couples the waves together involves the interaction of the carriers bunched by one of the waves with the fields induced by the other wave. The second process involves the interaction between a forward traveling ultrasonic wave and a microwave radiation field to generate a backward traveling ultrasonic wave (phonon echo) and an amplification of the forward traveling wave. In piezoelectric semiconductors in the presence of a d.c. electric field, the need for a threshold microwave field for the generation of the echo wave and the amplification of the forward traveling wave can be eliminated under certain circumstances.