We describe an active optical system that both measures and corrects the aberrations introduced when writing three-dimensional bit-oriented optical memory by a two-photon absorption process. The system uses a ferroelectric liquid-crystal spatial light modulator (FLCSLM) configured as an arbitrary wave-front generator that is reconfigurable at speeds as great as 2.5 kHz. A method of aberration measurement by the FLCSLM wave-front generator is described. The same device is also used to correct the induced aberrations by preshaping the wave fronts with the conjugate phase aberration as well as to scan the focal spot in three dimensions. Experimental results show the correction of both on- and off-axis aberrations, allowing the writing of data at depths as great as 1 mm inside a LiNbO<sub>3</sub> crystal.
© 2002 Optical Society of America
(010.1080) Atmospheric and oceanic optics : Active or adaptive optics
(210.2860) Optical data storage : Holographic and volume memories
(210.4680) Optical data storage : Optical memories
(220.1000) Optical design and fabrication : Aberration compensation
(230.6120) Optical devices : Spatial light modulators
Mark A. A. Neil, Rimas Juškaitis, Martin J. Booth, Tony Wilson, Tomokazu Tanaka, and Satoshi Kawata, "Active Aberration Correction for the Writing of Three-Dimensional Optical Memory Devices," Appl. Opt. 41, 1374-1379 (2002)