Experiments with photorefractive crystals for holographic interferometry

Abstract

Photorefractive crystals such as iron-doped lithium niobate are versatile recording materials for holographic interferometry. These crystals are self-developing, erasable, and reusable, amply sensitive in the visible region, and possess large information storage capacity, making them attractive for routine interferometry applications. This paper summarizes a variety of experiments in interferometry using iron-doped and undoped lithium niobate crystals for recording the holograms. Double-exposure holography with an argon laser is applied to visualize aerodynamic flow fields, heat transfer patterns, and acoustic waves. A pulsed Nd:YAG laser is used to visualize the details of turbulent aerodynamic fields. Finally, several heat transfer patterns are visualized by holographic subtraction interferometry and real-time interferometry.