Abstract
In this paper we review four photorefractive devices which have been investigated and further developed in our laboratories. We discuss the fundamental behavior of a photorefractive Bi12SiO20 autocorrelator optimized for particle image velocimetry. The all optical correlator determines the velocities of particles in a cross section of a flow. We show that the autocorrelator is perfect for investigating both laminar and turbulent flows. Photorefractive materials can also be used for vibration analysis of diffusely scattering structures. We discuss recent work from a four-wave mixing interferometric setup with Bi12SiO20 and show that introducing a proper sinusoidal phase shift in one of the pump beams leads to a complete mapping of the vibrational phase and amplitude everywhere on the vibrating structure. Photorefractive materials are also promising candidates for optical storage devices. We discuss holographic storage in LiNbO3 and describe a detailed procedure to obtain a high signal to noise ratio in this device. Finally, we discuss the photorefractive interference filter which consists of alternating quarter-wave layers of high and low index. It has a unique high wavelength selectivity, and the reflectivity and center wavelength can be controlled dynamically by two external laser beams.
Published Version
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