title: An exciton-polariton laser based on biologically produced fluorescent protein.
abstract: Under adequate conditions, cavity polaritons form a macroscopic coherent quantum state, known as polariton condensate. Compared to Wannier-Mott excitons in inorganic semiconductors, the localized Frenkel excitons in organic emitter materials show weaker interaction with each other but stronger coupling to light, which recently enabled the first realization of a polariton condensate at room temperature. However, this required ultrafast optical pumping, which limits the applications of organic polariton condensates. We demonstrate room temperature polariton condensates of cavity polaritons in simple laminated microcavities filled with biologically produced enhanced green fluorescent protein (eGFP). The unique molecular structure of eGFP prevents exciton annihilation even at high excitation densities, thus facilitating polariton condensation under conventional nanosecond pumping. Condensation is clearly evidenced by a distinct threshold, an interaction-induced blueshift of the condensate, long-range coherence, and the presence of a second threshold at higher excitation density that is associated with the onset of photon lasing.
authors.affiliation: Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.; Technische Physik, Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Christof P
authors.initials: CP
authors.lastname: Dietrich
authors.affiliation: Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
authors.forename: Anja
authors.initials: A
authors.lastname: Steude
authors.affiliation: Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Tropf
authors.affiliation: Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
authors.forename: Marcel
authors.identifier: 0000-0002-8739-4852
authors.initials: M
authors.lastname: Schubert
authors.affiliation: Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
authors.forename: Nils M
authors.initials: NM
authors.lastname: Kronenberg
authors.affiliation: Institut für Genetik, Technische Universität Dresden, 01062 Dresden, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Ostermann
authors.affiliation: Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.; Technische Physik, Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Höfling
authors.affiliation: Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK.
authors.forename: Malte C
authors.initials: MC
authors.lastname: Gather
mesh_terms: D049452:Green Fluorescent Proteins / Q000737:chemistry; D007834:Lasers; D008164:Luminescent Proteins / Q000737:chemistry*; D017785:Photons; D013057:Spectrum Analysis
chemical_list: D008164:Luminescent Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins
keywords: Polariton; bose-einstein; condensation; fluorescent protein; laser