  We describe a high-speed single-shot multi-frame interferometric imaging
technique enabling multiple interferometric images with femtosecond exposure
time over a 50 ns event window to be recorded following a single laser-induced
excitation event. The stroboscopic illumination of a framing camera is made
possible through the use of a doubling cavity which produces a femtosecond
pulse train that is synchronized to the gated exposure windows of the
individual frames of the camera. The imaging system utilizes a Michelson
interferometer to extract phase and ultimately displacement information. We
demonstrate the method by monitoring laser-induced deformation and the
propagation of high-amplitude acoustic waves in a silicon nitride membrane. The
method is applicable to a wide range of fast irreversible phenomena such as
crack branching, shock-induced material damage, cavitation and dielectric
breakdown.
