Acoustic time reversal with mode conversion at a solid-fluid interface

Abstract

Acoustic time-reversal experiments are mostly carried out in fluid media. This letter presents experiments proving the capability of a time-reversal mirror to obtain simultaneous focusing of both propagation modes inside a solid. The mirror is located in a surrounding fluid and records the longitudinal and transverse wavefronts (created by a laser impact on the solid) after conversion into pressure waves at the solid-fluid interface. We show that the time-reversed pressure wavefronts are reconverted mostly to their original propagation mode and focus simultaneously at the location of the laser impact.