Holographic interferometry using −1-order diffraction in photorefractive Bi_12SiO_20 and Bi_12TiO_20 crystals

Abstract

First-order diffraction from thin crystals of photorefractive Bi12SiO20 and Bi12TiO20 is investigated for application to real-time holographic interferometry. Enhancement of the first-order diffracted beam is achieved through the application of a square-wave alternating electric field to the crystals. Results of the dependence of first-order diffraction on experimental parameters are presented and are discussed in relation to the limits that they impose on the design of a real-time holographic interferometer. The resultant interferometer is applied to produce double-exposure interferograms of a simple object.