Abstract

Digital speckle-pattern interferometry (DSPI) using digital subtraction offers several advantages over conventional electronic speckle-pattern interferometry (ESPI) that utilizes high-pass filtering techniques.¹ However, previous approaches require the use of a reference beam which makes the system more complicated and sensitive to system instability. A new DSPI technique is introduced using a novel aperture sampling approach that does not require a reference beam. A real-time DSPI system employing this new approach is described and its applications in nondestructive testing are demonstrated.

© 1986 Optical Society of America