The working principle of interferometric vibrometers is based on the interference of light. A light beam, often a laser, is split into two paths: a reference beam and a measurement beam. The measurement beam is directed at the vibrating surface, while the reference beam remains unaffected. When the beams are recombined, the interference pattern created allows for the precise determination of the surface's displacement. The changes in the interference pattern are analyzed to measure the vibration amplitude and frequency.
