TRANSIENT DEFORMATION MEASUREMENT BY DOUBLE-PULSED-SUBTRACTION TV HOLOGRAPHY AND THE FOURIER-TRANSFORM METHOD

We report the measurement of transient bending waves with double-pulse d-subtraction TV holography. The correlation fringe patterns are autom atically quantitatively analyzed by the application of Fourier methods . A novel optical setup with two different object-beam optical paths i s demonstrated for the generation of carrier fringes. The proposed sys tem is highly immune to environmental disturbances because the optical setup imposes no lower limit on the time separation between laser pul ses. One removes the linear phase distribution due to the spatial carr ier in the spatial domain by subtracting the phase of the undeformed c arrier fringes from the phase of the modulated fringes. Experimental r esults obtained with an aluminum plate excited by the impact of a piez oelectric translator are presented. (C) 1998 Optical Society of Americ a.