Stoichiometric LiNbO3 for Optical Computing and Nonlinear Applications

Low scattering single crystal optical storage media are required for high-capacity (Tbit/cm3), high transfer rate (Gbitlsec) and sub-msec acces time holographic optical memories with low bit error rates (BER). The conventional (congruent) LiNbO3 is the most widely used holographic storage medium. It is usually grown by the Czochralski technique but can be grown by other growth methods. However, regardless of the growth technique of the congruent material, it always has a non-negligible inherent thermodynamic instability which leads to precipitates which become scattering centers. To achieve high density data storage in three dimensions we must prevent the formation of these unwanted metastable effects in the crystals. During crystal growth complete stoichiometry is necessary for all Li-Nb-O elements. To achieve this necessary condition a special quase-flux growth technique is proposed. In contrast to other stoichiometric growth methods, where certain improvements in the Li-Nb stoichiometry were achieved, our technique creates a special low melting phase in the melt to improve the oxygen stoichiometry as well. These fully stoichiometric-as grown-LiNbO3 crystals are especially promising for long-lasting, holographic data storage systems due to their extremely low scattering and very high thermodynamic stability. Stoichiometric lithiurn-niobate crystals for high-capacity holographic data storage systems with fast access times, fast transfer rates and low bit error rates offer many military and commercial applications. Fast intelligent shape recognition systems for military targets and intelligent robots are only two possible military applications. Sophisticated multi-media documents could be stored in a single piece of LiNbO for instance. Similarly, complete medical histories with digitally stored X-rays, graphic files, etc. of each patient could significantly improve the medical delivery system.