We report what is believed to be the first use of a photorefractive polymer in erasable–rewritable three-dimensional bit optical data storage under two-photon excitation. We successfully demonstrate writing, erasing, and rewriting of multilayered information in a photorefractive polymer consisting of 2,5-dimethyl-4-(<i>p</i>-nitrophenylazo)anisole, 2,4,7-trinitro-9-fluorenone, 9-ethylcarbazole, and poly(<i>N</i>-vinylcarbazole). A three-dimensional bit density of 5 Gbits/cm<sup>3</sup> is achieved by two-photon absorption under pulsed beam illumination at an infrared wavelength of 800 nm in the recording process. Complete erasing of the recording information is achieved by use of ultraviolet illumination.
© 1999 Optical Society of America
Daniel Day, Min Gu, and Andrew Smallridge, "Use of two-photon excitation for erasable–rewritable three-dimensional bit optical data storage in a photorefractive polymer," Opt. Lett. 24, 948-950 (1999)