STRAIN-BIASED FINE GRAIN ELECTROOPTIC CERAMIC DEVICE FOR CONTROLLING OPTICAL PHASE RETARDATION

摘要

A controllable optical phase retardation device includes a fine grain electrooptic ceramic plate, such as lanthanum doped lead zirconate-lead titanate. The plate is subjected to a constant and uniform strain with a tension axis in the plane of the plate, while a beam of optical radiation traverses the thickness of the plate. By applying voltages to a pair of transparent electrode layers located on opposed major surfaces of the plate, the degree of birefringence is controlled, that is, the relative optical phase retardation of the extraordinary and ordinary rays in the optical beam propagating through the plate is controllably varied by the electric fields perpendicular to the surfaces of the plate. This control over the phase retardation can be converted into optical intensity modulation or optical beam deflection by means of a conventional polarizer together with an optical analyzer or a doubly refracting prism.