Laser ultrasonics using photorefractive liquid crystals

Coaxial- and counter-optical setups for laser ultrasonics using a photorefractive liquid crystal were fabricated. The laser ultrasonics involves irradiating an object with a laser pulse to produce an ultrasonic vibration, and then using another laser beam to detect the vibration. The phase of the laser beam reflected from the object is shifted by the ultrasonic vibration. By using liquid crystals with photorefractive properties, the resulting phase shift of the laser beam reflected from the material can be detected. Compared to traditional laser ultrasonic methods, this system offers a simpler optical setup and allows for more precise measurements that are unaffected by environmental vibrations.