Digital speckle photography with the ring aperture diaphragm

In this paper theoretical and the experimental studies of application of optical systems with the ring apertures diaphragm in double-exposure speckle photography at the registration of the specklegram are presented. The application of optical systems with the ring apertures allows to increase sensitivity and to expand effective range at measurement of displacements by the double-exposure speckle photography. Theoretical estimates of the expansion of the range of measured displacements are presented. Experimental results of the analysis of interference patterns reconstructed by Young's method with double-exposure speckle photography confirming theoretical calculations are presented.