Advances in real-time holographic interferometry for the measurement of vibrations and deformations

We describe the latest improvements in holographic interferometry that enab le the real-time measurement of vibrational modes and static deformations i n surfaces using low-power laser illumination and a photorefractive Bi12TiO 20 crystal as the recording medium. An efficient setup has been developed w here the most critical elements have been optimized: target illumination an d backscattered light collection, distribution of light between the object and reference beams, and stabilization system operation. Experimental resul ts for vibration and deformatiom measurement are reported. (C) 2000 Elsevie r Science Ltd. All rights reserved.