DIGITAL DOUBLE-PULSED HOLOGRAPHIC-INTERFEROMETRY FOR VIBRATION ANALYSIS

In this paper we describe a digital double-pulsed holographic system. Two separate holograms of an object under test are recorded within a few microseconds using a charge-coupled device camera and stored in a frame grabber. The holograms are digitally reconstructed using a computer, by simulation of the Fresnel diffraction of the hologram illuminated by the reference wave. The phases of the two reconstructed wave fields are calculated from the complex amplitude and the deformation is obtained from the phase difference. Experimental results are presented.