Single-aperture speckle shearing interferometry with a single grating.

A simple method for measuring the displacement-slope distribution is proposed, and its usefulness is verified experimentally. In this method we use a single-aperture recording system with only one grating. The grating forms a spatial carrier of high spatial frequency inside speckles in the image and also shears the images. The sheared images are doubly recorded on the photoplate before and after deformation of the object. Clear fringes are obtained by filtering this plate. This method gives us fringes indicating the slope distribution. It is verified experimentally that these fringes indicate the slope distribution with sufficient accuracy.