Compact and portable holographic camera using photorefractive crystals. Application in various metrological problems

We present a compact holographic interferometer that uses a photorefractive crystal of the sillenite family as a holographic recording medium. Its dev elopment is based on a previous prototype that showed lack of flexibility a nd portability. We briefly discuss the main improvements leading to a compa ct device. Applications of this instrument in various metrological problems are shown, among which are two that were not already considered using holo graphy, namely measurement of a thermal expansion coefficient and detection of fingerprints.