Recent Advances in Holographic Strain and Stress Measurement

Abstract

AbstractHolography allows the capture and reconstruction of whole wave fields with intensity and phase. The interferometric comparison of holographically reconstructed wave fields enables high-precision deformation measurements of diffusely reflecting surfaces, which has a lot of applications in experimental strain and stress analysis as well as in nondestructive testing. Digital holography gives the user the chance to decide during the reconstruction process, which plane he wants to focus. Here we show digital holography applied in microscopy, in particle analysis, in deformation measurements, and in the measurement of refractive index distributions of optical fibers. Recently spatial light modulators have been introduced to holography, thus varying the reference wave without mechanical movement of components. Here we present spatial light modulators used in digital shearography as well as in a flexible lensless Fourier-transform holography system together with measurement results obtained with these concepts.KeywordsWave FieldSpatial Light ModulatorReference WaveHolographic InterferometryObject WaveThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.