title: Tuning the Quantum Efficiency of Random Lasers - Intrinsic Stokes-Shift and Gain.
abstract: We report the theoretical analysis for tuning the quantum efficiency of solid state random lasers. Vollhardt-Wölfle theory of photonic transport in disordered non-conserving and open random media, is coupled to lasing dynamics and solved positionally dependent. The interplay of non-linearity and homogeneous non-radiative frequency conversion by means of a Stokes-shift leads to a reduction of the quantum efficiency of the random laser. At the threshold a strong decrease of the spot-size in the stationary state is found due to the increase of non-radiative losses. The coherently emitted photon number per unit of modal surface is also strongly reduced. This result allows for the conclusion that Stokes-shifts are not sufficient to explain confined and extended mode regimes.
authors.affiliation: Electrical Engineering, Precision Engineering, Information Technology, Georg-Simon-Ohm University of Applied Sciences, Kesslerplatz 12, 90489 Nürnberg, Germany.|Physikalisches Institut, Rheinische Friedrich-Wilhelms Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lubatsch
authors.affiliation: Institute of Theoretical Physics, Optics and Photonics, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany.|Institute of Solid State Physics, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede Strasse 1, 76131 Karlsruhe, Germany.
authors.forename: Regine
authors.initials: R
authors.lastname: Frank