An optical lateral-shearing device utilizes two prisms to define a wedge with a wedge angle that produces a lateral displacement of incident beam over a wide dynamic beam size range. The three operating surfaces of each prism are specifically inclined with respect to each other in such a way that unwanted beam reflections are eliminated, the amount of shear per unit separation is increased, and the intensity and contrast output beam are enhanced. The wedge thickness and tilt can be varied to maintain high sensitivity over the wide beam size range. The device can be rotated to perform phase-shifting interferometric analysis in conventional manner.