Full-field characterization of surface vibrations in microacoustic components by supercontinuum laser stroboscopic white-light interferometry

We present phase-sensitive absolute amplitude measurements of surface vibrations in microacoustic devices using a supercontinuum based stroboscopic white-light interferometer. The setup enables full-field characterization of out-of-plane vibration fields down to sub-100 pm amplitudes and up to GHz range, the highest detectable frequency limited only by the duration of the 300 ps light pulses. The capabilities of the system are demonstrated by measuring a vibration field in a square-plate silicon MEMS resonator at a 3.4 MHz resonance. The maximum vibration amplitude was measured to be 40 nm, and a minimum detectable amplitude limit of less than 100 pm was obtained.