Dynamic Holographic Interferometry: Devices and Applications

Abstract

This chapter is a review of photorefractive crystals used in holographic interferometry, starting from the basics and early experiments up to devices achievement. We first recall the basics of holographic interferometry and describe the most important pioneering experiments that showed the tremendous potentialities of photorefractive crystals as dynamic recording media for this technique. We then present the main requirements for the development of a holographic interferometer and we analyze the figures of merit and the properties of different photorefractive crystals for that purpose. We emphasize the implementation of the phasequantification techniques because they give access to displacement metrology. The next sections are devoted to the presentation of metrological devices based on dynamic holographic interferometry with sillenite crystals. The first system is a holographic camera with a continuous laser adapted to the study of displacement of scattering objects. We present its main development steps and show that it is highly versatile and can be used in the observation of different types of phenomena. The second range of devices allows the observation of transparent objects: one is especially studied for use in microgravity fluid experiments and the second is an adaptation of the first system for scattering objects to the observation of transparent objects. The third system uses pulsed lasers with applications focused on the study of structure vibrations.