Time-averaged holographic interferometry using subtraction digital holography

Time-averaged holographic interferometry is a known technique frequently used for analyzing vibration properties of objects. The development of array photo-detectors allowing long integration times enabled the capture of time-averaged holograms. A new technique called 'subtraction digital holography' has been recently developed for suppressing the zero-order disturbance in off-axis digital holography. In this work, we combine the time-averaged principle with subtraction digital holography technique. Results for a torsional micro-electro-mechanical systems (MEMS) and an oscillating membrane demonstrate clear hologram reconstructions covered with high-contrast fringes that describe the vibration modes.