Acousto-optic methods for investigation of elastic properties of crystals from the langasite family

A great interest recently shown to crystals from the langasite family is a result of the combination of their unique properties and promising feature for those materials used in resonators, filters, and sensors in many fields of technology. Crystals from this family have very versatile compositions and types, they are produced at many different production facilities, and therefore, they require fast methods for the estimation and measurements of their elastic characteristics and properties. An acousto-optic method, which uses the phenomenon of a monochromatic optical wave diffraction by a periodical structure generated by a traveling acoustic wave, may be one of the most promising characterization methods. It requires minimum number of crystal samples and orientations, at the same time it yields complete information on elastic properties.