AN INPLANE INSENSITIVE MULTIAPERTURE SPECKLE SHEAR INTERFEROMETER FORSLOPE MEASUREMENT

A modified two-aperture speckle shear interferometer that eliminates t he contribution of the in-plane component and its derivative to the ph ase change, and yields a fringe pattern corresponding to the first-ord er partial derivatives of the out-of-plane displacement component, is reported in this note. In this method, two laterally sheared object po ints are viewed axially. The wave fields from these points ave indepen dently combined at the image plane of the imaging system. (C) 1998 Els evier Science Ltd. All rights reserved.