Deformable mirror using the PMN electrostrictor

A simple deformable bimorphous mirror using the PMN electrostrictor has been made for refocusing a light beam. Parabolic deformation of the mirror has been measured by an interferometric technique on a cycle with rising and falling electric fields. In comparison with the hard PZT piezostrictor, the electrostrictor is found to be promising for practical mirror control applications because of a large strain with neither hysteresis nor aging effects.