Piezoelectric deformable mirrors and gratings

摘要

An apparatus and method for rapidly and accurately positioning an optical surface comprises at least one piezoelectric element 10 with an optical surface 16 located thereon and means 12,30 for applying an electric field to the piezoelectric element 10. The piezoelectric element 10 is piezoelectrically polarized along a first axis and the electric field is supplied along a second axis perpendicular to the first axis. Thus, piezoelectric shear deformation of the piezoelectric element occurs and there is rotation of the optical surface 16 about a third axis which is perpendicular to both the first and second axes. The deformation is sufficient to alter the direction of incident radiation and to alter the direction and distribution of diffracted incident radiation after interaction with the optical surface 16. Varying the magnitude of the electric field alters the magnitude of the deformation thereby accurately positioning the optical surface 16.