A two-dimensional in-plane displacement-sensitive electronic speckle pattern interferometer has been developed. With a fiber coupler with one input and four outputs, two sets of dual-beam interferometric configurations in orthogonal directions are constructed to determine in-plane displacements completely. When a CCD camera with a zoom lens is located at an adequate distance from the specimen, a testing area ranging from 1.4 mm × 1.0 mm to 30.0 mm × 24.0 mm can be examined in quasi-real-time. Incorporated with the hole-drilling technique, it has currently been demonstrated in residual stress measurements. One application is for determining the residual stress of a thick cylinder consisting of two concentric circular tubes with interference fit. The other is for analyzing the residual stress distribution of a recordable optical compact disc. A simple approach to interpreting the values of residual stresses from the displacement contours is presented.
© 1998 Optical Society of America
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.6160) Instrumentation, measurement, and metrology : Speckle interferometry
(210.4590) Optical data storage : Optical disks
Jingbo Zhang and Tow Chong Chong, "Fiber Electronic Speckle Pattern Interferometry and its Applications in Residual Stress Measurements," Appl. Opt. 37, 6707-6715 (1998)