Bismuth tellurite - a new material for holographic memory

The photorefractive properties of Bi2TeO5 crystals were measured with the w ave mixing technique using the 532 nm output of a Nd:YAG laser for writing gratings. The saturation diffraction efficiency of the grating for the opti mum crystal orientation and beam polarization configuration exceeded the 40 %. Above a threshold write intensity, a remarkable fraction (10-20%) of the saturation diffraction efficiency remained stable for several days in the crystal. A weaker read beam of the same wavelength did not erase the gratin g. A two-dimensional holographic image was also written into the Bi2TeO5 cr ystals for the first time. (C) 2000 Elsevier Science B.V. All rights reserv ed.