INFLUENCE OF AN EXTERNALLY APPLIED MAGNETIC-FIELD ON VECTORIAL INTERACTION IN LINBO3-FE CRYSTALS

An experimental investigation of the influence of an externally applie d magnetic field on the dynamic grating formation in iron-doped lithiu m niobate is carried out. The diffraction efficiency and the two-beam gain depends strongly on the applied magnetic field. We observe change s in the two-beam gain and the diffraction efficiency of up to 40 and 75 %, respectively. The magnitude depends on the direction of the magn etic field. The interaction is believed to occur due to the anomalousl y high mobility of the nonthermalized free electrons responsible for t he photovoltaic current, which in the vectorial interaction scheme cau ses the grating formation. A phenomenological description of the photo voltaic current including the photo-flail effect shows a linear depend ence on the magnetic field, which does not explain the obtained experi mental results.