Transient wave fields in mechanics and acoustics recorded by pulsed TV holography

Pulsed TV holography is a newly developed technique for visualization of transient phenomena like propagating bending waves in structures and acoustic waves in fluids. The holograms are captured directly on successive frames of a CCD-detector. Quantitative data of the phase difference between two recordings is obtained by a Fourier-transform method. No chemical processing and optical hologram reconstruction are needed as in traditional holographic interferometry. The system is demonstrated in experiments with transient bending waves in the violin and acoustic waves in air radiating from an impacted plate. A circular symmetric projection of the acoustic field is recorded. The symmetry allows a tomographic reconstruction of the three-dimensional field to be performed using this single projection.