Application of a locally operating laser-speckle strain sensor

In this paper, we report on both the theory and applicability of a novel laser-speckle shift strain measurement system. Based on the theoretical sensitivity of the system to strain, some sources of error due to imperfections in the geometrical setup are discussed. Some references to the digital signal processing involved are given. We conclude with some experimental results from testing fibers, foils, and standardized specimen that can only be obtained in a noncontacting and preferably optical way because of the fragility and the small physical dimensions of the specimen.