title: Biomolecular optical data storage and data encryption.
abstract: The use of bacteriorhodopsin (BR) as an active layer in write-once-read-many optical storage is presented. This novel feature of BR materials may be used on a wide variety of substrates, among them transparent substrates but also paper and plastics. The physical basis of the recording process is polarization-sensitive two-photon absorption. As an example for this new BR application, an identification card equipped with an optical recording strip is presented, which has a capacity of about 1 MB of data. The recording density currently used is 125 kB/cm2, which is far from the optical limits but allows operation with cheap terminals using plastic optics. In the examples given, data are stored in blocks of 10 kB each. A special optical encryption procedure allows the stored data to be protected from unauthorized reading. The molecular basis of this property is again the polarization-sensitive recording mechanism. The unique combination of optical storage, photochromism, and traceability of the BR material is combined on the single-molecule level. BR introduces a new quality of storage capability for applications with increased security and anticounterfeiting requirements.
authors.affiliation: Institute of Physical Chemistry, Department of Chemistry, University of Marburg, D-35032 Marburg, Germany. fischert@mailer.uni-marburg.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Fischer
authors.forename: Martin
authors.initials: M
authors.lastname: Neebe
authors.forename: Thorsten
authors.initials: T
authors.lastname: Juchem
authors.forename: Norbert A
authors.initials: NA
authors.lastname: Hampp
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry* / Q000528:radiation effects*; D016494:Computer Security; D039301:Computers, Molecular; D001330:Electronic Data Processing / Q000295:instrumentation / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D007834:Lasers; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D055095:Optics and Photonics / Q000295:instrumentation; D010777:Photochemistry / Q000295:instrumentation / Q000379:methods*
chemical_list: D001436:Bacteriorhodopsins