Explosive instability of ultrasonic triads under frequency modulated electromagnetic pumping

摘要

Explosive dynamics of three- phonon bound excitations in ultrasound frequency band is studied experimentally and theoretically on an example of magnetic medium under homogeneous electromagnetic pumping. Development of ultrasonic explosion is distorted by nonlinear acoustic effects in particular by nonlinear frequency shift of generated waves. It is shown in the present paper that a proper choice of frequency modulation of electromagnetic pumping allows to compensate the nonlinear frequency shift of acoustic vibrations and to reveal the quasi- singular amplification typical for explosive instability.