7 research outputs found
THE AMPLITUDE-PHASE DISTORTION AT THE PARAMETRIC SOUND WAVE CONJUGATION
We investigate the amplitude distortion of the contrary phase-conjugated wave, generated in the active plane-parallel parametric layer by the incident acoustic beam with Hauss transverse profile. We treat both stable and unstable regimes
PHASE CONJUGATION OF ACOUSTIC WAVES IN SEMICONDUCTORS
We discuss a new mechanism of phase conjugation in acoustics based on phonon-plasmon interaction in the conditions when the conduction electrons density is modulated in time. Such modulation can be realized by periodic laser illumination of the sample or due to Zinner's transitions in the external alternating electric field
EMITTING OF PHASE CONJUGATE ULTRASOUND WAVE INTO LIQUID BY PARAMETRICALLY EXCITED FERRITE
Phase conjugate sound waves at 6 MHz generated by polycrystalline ferrite sample at conditions of parametric magnetic field pumping over the threshold of absolute instability were studied in liquid. Conforming images of phase fronts for incident and conjugate waves were obtained. An angular anisotropy of effectivity connected with sample geometry was discovered and a method for it smoothing out is proposed. Maximum gain of acoustic wave in water was 43 dB ( 60 dB in ferrite )
GIANT REGENERATIVE AMPLIFICATION WITH SOUND WAVE PHASE CONJUGATION IN FERRITE
New result of investigations of the parametrical sound wave phase conjugation (WPC) phenomena in magnets are reported