Whole-field vibration phase measurement with electronic speckle pattern interferometry (ESPI)

A stroboscopically illuminated ESPI system is described for the simultaneous measurement of vibration amplitude and phase. The technique involves modulating both the illumination pulse phase relative to the vibration, and the optical phase of the interferometer reference beam to generate eight video frames which are processed to yield vibration amplitude and phase.Science and Engineering Research Council (UK)Department of Trade and Industry (UK)Xunta de Galici