title: High-speed integrated optical logic based on the protein bacteriorhodopsin.
abstract: The principle of all-optical logical operations utilizing the unique nonlinear optical properties of a protein was demonstrated by a logic gate constructed from an integrated optical Mach-Zehnder interferometer as a passive structure, covered by a bacteriorhodopsin (bR) adlayer as the active element. Logical operations were based on a reversible change of the refractive index of the bR adlayer over one or both arms of the interferometer. Depending on the operating point of the interferometer, we demonstrated binary and ternary logical modes of operation. Using an ultrafast transition of the bR photocycle (BR-K), we achieved high-speed (nanosecond) logical switching. This is the fastest operation of a protein-based integrated optical logic gate that has been demonstrated so far. The results are expected to have important implications for finding novel, alternative solutions in all-optical data processing research.
authors.affiliation: Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, PO Box 521, 6701 Szeged, Hungary.
authors.forename: Anna
authors.initials: A
authors.lastname: Mathesz
authors.forename: László
authors.initials: L
authors.lastname: Fábián
authors.forename: Sándor
authors.initials: S
authors.lastname: Valkai
authors.forename: Daniel
authors.initials: D
authors.lastname: Alexandre
authors.forename: Paulo V S
authors.initials: PV
authors.lastname: Marques
authors.forename: Pál
authors.initials: P
authors.lastname: Ormos
authors.forename: Elmar K
authors.initials: EK
authors.lastname: Wolff
authors.forename: András
authors.initials: A
authors.lastname: Dér
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry*; D004867:Equipment Design; D007368:Interferometry / Q000295:instrumentation*; D055095:Optics and Photonics / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*
chemical_list: D001436:Bacteriorhodopsins