Anisotropic diffraction configuration using BSO photorefractive crystal for detection of laser ultrasonic

Green region of spectrum is one of most promising for interferometric applications since the sensitivity grows with reduction of wavelength, and powerful CW lasers are commercially available now. Photorefractive Bi12SiO20 (BSO) crystal is the most sensitive one in this spectral region, which makes it attractive for adaptive detection of laser ultrasonic via two-wave mixing (TWM). We report basic dependencies of TWM of phase modulated beams in this PRC in its conventional holographic (110) cut (in particular on external dc field, input light polarization etc.). Since the amplitude noise of laser is usually dominating, the sensitivity of the whole system can be essentially increased using anisotropic (i.e. with polarization plane rotation) light diffraction in BSO.