The origins of the field date back to the 1950s, when Yehuda Hirshberg developed the photochromicspiropyrans and suggested their use in data storage. In the 1970s, Valerii Barachevskii demonstrated that this photochromism could be produced by two-photon excitation, and at the end of the 1980s Peter M. Rentzepis showed that this could lead to three-dimensional data storage.
Processes for reading data
Second-harmonic generation has been demonstrated as a method to read data written into a poled polymer matrix.
Masahiro Irie developed the diarylethene family of photochromic materials.
Yoshimasa Kawata, Satoshi Kawata, and Zouheir Sekkat have developed and worked on several optical data manipulation systems, in particular involving poled polymer systems.
Kevin C Belfield is developing photochemical systems for 3D optical data storage by the use of resonance energy transfer between molecules, and also develops high two–photon cross-section materials.
Tom Milster has made many contributions to the theory of 3D optical data storage.
Min Gu has examined confocal readout and methods for its enhancement.
Commercial development
Examples of 3D optical data storage media. Top row– written Call/Recall media; Mempile media. Middle row– FMD; D-Data DMD and drive. Bottom row– Landauer media; Microholas media in action.
Call/Recall was founded in 1987 on the basis of Peter Rentzepis' research. Using two–photon recording (at 25Mbit/s with 6.5ps, 7nJ, 532nm pulses), one–photon readout (with 635nm), and a high NA (1.0) immersion lens, they have stored 1TB as 200layers in a 1.2mm thick disk. They aim to improve capacity to >5TB and data rates to up to 250Mbit/s within a year, by developing new materials as well as high-powered pulsed blue laser diodes.
Mempile was developing a commercial system with the name TeraDisc. In March 2007, they demonstrated the recording and readback of 100 layers of information on a 0.6mm thick disc, as well as low crosstalk, high sensitivity, and thermodynamic stability. They intended to release a red-laser 0.6-1.0 TB consumer product in 2010, and have a roadmap to a 5 TB blue-laser product.
Constellation 3D developed the Fluorescent Multilayer Disc at the end of the 1990s, which was a ROM disk, manufactured layer by layer. The company failed in 2002, but the intellectual property (IP) was acquired by D-Data Inc., who are attempting to introduce it as the Digital Multilayer Disk (DMD).
Landauer Inc. are developing a media based on resonant two-photon absorption in a sapphire single crystal substrate. In May 2007, they showed the recording of 20 layers of data using 2 nJ of laser energy (405nm) for each mark. The reading rate is limited to 10Mbit/s because of the fluorescence lifetime.
Colossal Storage aim to develop a 3D holographic optical storage technology based on photon-induced electric field poling using a far UV laser to obtain large improvements over current data capacity and transfer rates, but as yet they have not presented any experimental research or feasibility study.
Microholas operates out of the University of Berlin, under the leadership of Prof Susanna Orlic, and has achieved the recording of up to 75layers of microholographic data, separated by 4.5 micrometres, and suggesting a data density of 10GB per layer.
3DCD Technology Pty. Ltd. is a university spin-off set up to develop 3D optical storage technology based on materials identified by Daniel Day and Min Gu.
↑Kawata, S.; Kawata, Y. (2000). "Three-Dimensional Optical Data Storage Using Photochromic Materials". Chemical Reviews. 100 (5): 1777–88. doi:10.1021/cr980073p. PMID11777420.
↑Burr, G.W. (2003). Three-Dimensional Optical Storage(PDF). SPIE Conference on Nano-and Micro-Optics for Information Systems. pp.5225–16. Archived from the original(PDF) on March 8, 2008.
↑Hirshberg, Yehuda (1956). "Reversible Formation and Eradication of Colors by Irradiation at Low Temperatures. A Photochemical Memory Model". Journal of the American Chemical Society. 78 (10): 2304–2312. doi:10.1021/ja01591a075.
↑Mandzhikov, V. F.; Murin, V. A.; Barachevskii, Valerii A. (1973). "Nonlinear coloration of photochromic spiropyran solutions". Soviet Journal of Quantum Electronics. 3 (2): 128. doi:10.1070/QE1973v003n02ABEH005060.
↑Fort, A. F.; Barsella, A.; Boeglin, A. J.; Mager, L.; Gindre, D.; Dorkenoo, K. D. (29 August 2007). Optical storage through second harmonic signals in organic films. SPIE Optics+Photonics. San Diego, US. pp.6653–10.
↑Irie, Masahiro (2000). "Diarylethenes for Memories and Switches". Chemical Reviews. 100 (5): 1685–716. doi:10.1021/cr980069d. PMID11777416.
↑Kawata, Y.; Kawata, S. (23 October 2002). "16: 3D Data Storage and Near-Field Recording". In Sekkat, Z.; Knoll, W. (eds.). Photoreactive Organic Thin Films. US: Elsevier. ISBN0-12-635490-1.
↑Amistoso, Jose Omar; Gu, Min; Kawata, Satoshi (2002). "Characterization of a Confocal Microscope Readout System in a Photochromic Polymer under Two-Photon Excitation". Japanese Journal of Applied Physics. 41 (8): 5160–5165. Bibcode:2002JaJAP..41.5160A. doi:10.1143/JJAP.41.5160. S2CID121467147.
↑Shipway, Andrew N.; Greenwald, Moshe; Jaber, Nimer; Litwak, Ariel M.; Reisman, Benjamin J. (2006). "A New Medium for Two-Photon Volumetric Data Recording and Playback". Japanese Journal of Applied Physics. 45 (2B): 1229–1234. Bibcode:2006JaJAP..45.1229S. doi:10.1143/JJAP.45.1229. S2CID59161795.
↑Akselrod, M. S.; Orlov, S. S.; Sykora, G. J.; Dillin, K. J.; Underwood, T. H. (2007). Progress in Bit-Wise Volumetric Optical Storage Using Alumina-Based Media. Optical Data Storage. The Optical Society of America. doi:10.1364/ODS.2007.MA2.
