Abstract
A development of a DC servo motor driven phase shifting equipment for a phase shift shearing interferometer is reported. A shearing interferometer is often used for precise surface measurement, optical wave front measurement and so on. In a plane parallel plate type of shearing interferometer, a glass plate makes laterally sheared beam from the induced test beam. Then interferogram which reflects the phase distribution of the wave front of the induced beam is produced. Phase shifting technique is applied to analyze interference fringe. The phase shifting can be induced by tilting shear plate using DC servo motor driven rotational stage. This phase shifting mechanism is much cheaper than usual equipment using PZT actuators. A result of measurement for an aspherical lens is also reported.
