Three-dimensional digital holography with three object-illuminating beams has been successfully used for the detection of surface strain in metallic objects. The optical setup that uses illuminating beams to irradiate the object from three directions means that all three object surface displacement components, x, y, and z, can be independently calculated and used to find the strain gradients on the surface. The results show the conversion of the complete surface displacement field into a surface strain field. The method is capable of measuring microstrains for out-of-plane surface displacements of less than 10 µm.
© 2005 Optical Society of America
(090.2880) Holography : Holographic interferometry
(120.4290) Instrumentation, measurement, and metrology : Nondestructive testing
(120.6160) Instrumentation, measurement, and metrology : Speckle interferometry
Manuel De la Torre-Ibarra, Fernando Mendoza-Santoyo, Carlos Pérez-López, and Tonatiuh Saucedo-A., "Detection of surface strain by three-dimensional digital holography," Appl. Opt. 44, 27-31 (2005)