2024-03-29T12:55:25Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/147612022-11-17T02:08:08Zhdl_2115_20044hdl_2115_124All-optical switching in Pharaonis phoborhodopsin protein molecules.Roy, SukhdevKikukawa, TakashiSharma, ParagKamo, NaokiBacteriorhodopsinoptical modulationoptical switching464.2Low-power all-optical switching with pharaonis phoborhodopsin (ppR) protein is demonstrated based on nonlinear excited-state absorption at different wavelengths. A modulating pulsed 532-nm laser beam is shown to switch the transmission of a continuous-wave signal light beam at: 1) 390 nm; 2) 500 nm; 3) 560 nm; and 4) 600 nm, respectively. Simulations based on the rate equation approach considering all seven states in the ppR photocycle are in good agreement with experimental results. It is shown that the switching characteristics at 560 and 600 nm, respectively, can exhibit negative to positive switching. The switching characteristics at 500 nm can be inverted by increasing the signal beam intensity. The profile of switched signal beam is also sensitive to the modulating pulse frequency and signal beam intensity and wavelength. The switching characteristics are also shown to be sensitive to the lifetimes of$mmb pbf pR_bf M$and$mmb pbf pR_bf O$intermediates. The results show the applicability of ppR as a low-power wavelength tunable all-optical switch.IEEEJournal Articleapplication/pdfhttp://hdl.handle.net/2115/14761https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/14761/1/IEEE5-3.pdf1536-1241IEEE Transactions on Nanobioscience531781872006-09enginfo:pmid/16999243info:doi/10.1109/TNB.2006.880828©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. IEEE, IEEE Transactions on Nanobioscience, vol. 5-3, 2006, 178-187publisher