Room temperature broadband polariton lasing from a dye‐filled microcavity

A material system is proposed to generate polariton lasing at room temperature over a broad spectral range. The system developed is based on a boron‐dipyrromethene fluorescent dye (BODIPY‐G1) that is dispersed into a polystyrene matrix and used as the active layer of a strongly coupled microcavity. It is shown that the BODIPY‐G1 exciton polaritons undergo nonlinear emission over a broad range of exciton–cavity mode detuning in the green‐yellow portion of the visible spectrum, with polariton lasing achieved over a spectral range spanning 33 nm. The recorded linewidth of ≈0.1 nm corresponds to a condensate coherence lifetime of ≈1 ps. It is proposed that similar effects can be anticipated using a range of molecular dyes in the BODIPY family; a result that paves the way for tunable polariton devices over the visible and near‐infrared spectral region

Mechanisms of blueshifts in organic polariton condensates

This is the final version. Available from Nature Research via the DOI in this record.The data that support the findings of this study are available in University of Southampton Institutional Repository with the identifier https://doi.org/10.5258/SOTON/D1159.Bose-Einstein condensates of exciton-polaritons in inorganic semiconductor microcavities are known to possess strong interparticle interactions attributed to their excitonic component. The interactions play a crucial role in the nonlinear dynamics of such systems and can be witnessed as the energy blueshifts of polariton states. However, the localised nature of Frenkel excitons in strongly coupled organic microcavities precludes interparticle Coulomb exchange-interactions that change mechanisms of the nonlinearity and blueshifts accordingly. In this report, we unravel the origins of blueshifts in organic polariton condensates. We examine the possible contributions: intracavity optical Kerr-effect, gain-induced frequency-pulling, polariton interactions and effects related to saturation of optical transitions for weakly- and strongly-coupled molecules. We conclude that blueshifts in organic polariton condensates arise from the interplay of the saturation effects and intermolecular energy migration. Our model predicts the commonly observed step-like increase of both the emission energy and degree of linear polarization at the polariton condensation threshold.Russian Scientific Foundation (RSF)Government of the Russian FederationGovernment of the Russian FederationEngineering and Physical Sciences Research Council (EPSRC)ITMO Fellowship Progra

On the origin of blueshifts in organic polariton condensates

We report on the origin of energy-shifts in organic polariton condensates. The localised nature of Frenkel excitons in molecular semiconductors precludes interparticle Coulomb exchange interactions -the latter being the dominant mechanism for blueshifts in inorganic semiconductor microcavities that bear Wannier-Mott excitons. We examine the contribution of optically induced change of the intracavity non-linear refractive index, gain induced frequency-pulling and quenching of the Rabi splitting, as well as the role of polariton-exciton and polariton-polariton scattering in the energy-shift of the polariton mode at condensation threshold in strongly coupled molecular dye microcavities. We conclude that blueshifts in organic polariton condensates arise from the interplay of the saturation of molecular optical transitions and intermolecular energy migration. Our model predicts the commonly observed step-wise increase of both the emission energy and degree of linear polarisation at polariton condensation threshold

Room temperature lasing in injection microdisks with InGaAsN/GaAs quantum well active region

Injection microdisk lasers based on three InGaAsN/GaAs quantum wells with different diameters of the resonator were fabricated and studied. Room temperature lasing at 1.2 μm is demonstrated for the first time. Dependence of the threshold current on the diameter is discussed.publishedVersionPeer reviewe