Photorefractive phase coupling measurement using self-stabilized recording technique

The measurement of the phase shift (p between the transmited and difracted beams interfering along the same direction behind the hologram recorded in a photorefractive crystal is directly and accurately measured using a self-stabilized recording technique. The measured phase shift as a function of the applied electric field allows computing the Debye screening lenght and the effectively applied field coefficient of an undoped Bi12TiO20 crystal. The result is in good agreement with the already available information about this sample.