title: Optical gating with organic building blocks. A quantitative model for the fluorescence modulation of photochromic perylene bisimide dithienylcyclopentene triads.
abstract: We investigated the capability of molecular triads, consisting of two strong fluorophores that were covalently linked to a photochromic molecule, for optical gating. Therefore we monitored the fluorescence intensity of the fluorophores as a function of the isomeric state of the photoswitch. From the analysis of our data we develop a kinetic model that allows us to predict quantitatively the degree of the fluorescence modulation as a function of the mutual intensities of the lasers that are used to induce the fluorescence and the switching of the photochromic unit. We find that the achievable contrast for the modulation of the fluorescence depends mainly on the intensity ratio of the two light beams and appears to be very robust against absolute changes of these intensities. The latter result provides valuable information for the development of all-optical circuits which would require to handle different signal strengths for the input and output levels.
authors.affiliation: Experimental Physics IV, University of Bayreuth 95440 Bayreuth, Germany.
authors.forename: Martti
authors.initials: M
authors.lastname: Pärs
authors.affiliation: Experimental Physics IV, University of Bayreuth 95440 Bayreuth, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Gradmann
authors.affiliation: Applied Functional Polymers, University of Bayreuth 95440 Bayreuth, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Gräf
authors.affiliation: 1] Applied Functional Polymers, University of Bayreuth 95440 Bayreuth, Germany [2].
authors.forename: Peter
authors.initials: P
authors.lastname: Bauer
authors.affiliation: Applied Functional Polymers, University of Bayreuth 95440 Bayreuth, Germany.
authors.forename: Mukundan
authors.initials: M
authors.lastname: Thelakkat
authors.affiliation: Experimental Physics IV, University of Bayreuth 95440 Bayreuth, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Köhler