The two-color recording sensitivity <i>S</i> and the figure of merit <i>M</i>/# are measured in a reduced and congruent LiNbO<sub>3</sub>:In crystal of 2.2-mm thickness. The results are compared with those before reduction treatment. It is found that <i>S</i> increases by an order of magnitude through reduction treatment but the <i>M</i>/# is unchanged. Measured values for <i>S</i> and <i>M</i>/# in the reduced crystal are found to be 3 × 10<sup>−3</sup> cm/J and 0.04, respectively, with a total writing intensity of 4.0 W/cm<sup>2</sup> at 780 nm and a gating intensity of 1.15 W/cm<sup>2</sup> at 488 nm. These values are close to those of near-stoichiometric LiNbO<sub>3</sub> crystals under similar recording conditions. We also show that photoconductivity plays an important role in the improvement of <i>S</i> in LiNbO<sub>3</sub>:In.
© 2001 Optical Society of America
(160.2900) Materials : Optical storage materials
(160.5320) Materials : Photorefractive materials
(190.5330) Nonlinear optics : Photorefractive optics
(210.2860) Optical data storage : Holographic and volume memories
(210.4810) Optical data storage : Optical storage-recording materials
Guoquan Zhang, Steven Sunarno, Mitsunari Hoshi, Yasuo Tomita, Chunhui Yang, and Wusheng Xu, "Characterization of Two-Color Holography Performance in Reduced LiNbO3:In," Appl. Opt. 40, 5248-5252 (2001)