We propose a new method for measuring large-object deformations byusing temporal evolution of the speckles in speckleinterferometry. The principle of the method is that by deformingthe object continuously, one obtains fluctuations in the intensity ofthe speckle. A large number of frames of the object motion arecollected to be analyzed later. The phase data for whole-objectdeformation are then retrieved by inverse Fourier transformation of afiltered spectrum obtained by Fourier transformation of thesignal. With this method one is capable of measuring deformationsof more than 100 μm, which is not possible using conventionalelectronic speckle pattern interferometry. We discuss theunderlying principle of the method and the results of theexperiments. Some nondestructive testing results are alsopresented.
© 1998 Optical Society of America
[Optical Society of America ]
(030.6140) Coherence and statistical optics : Speckle
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.4290) Instrumentation, measurement, and metrology : Nondestructive testing
C. Joenathan, B. Franze, P. Haible, and H. J. Tiziani, "Speckle Interferometry with Temporal Phase Evaluation for Measuring Large-Object Deformation," Appl. Opt. 37, 2608-2614 (1998)