Microcavity design for low threshold polariton condensation with ultrashort optical pulse excitation

• Published in: Journal of applied physics 2015-05, Vol.117 (20)
• Main Authors: Poellmann, C., Leierseder, U., Galopin, E., Lemaître, A., Amo, A., Bloch, J., Huber, R., Ménard, J.-M.
• Format: Article
• Language: English
• Subjects: ALUMINIUM ARSENIDES; Applied physics; COMPARATIVE EVALUATIONS; Condensation; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; EFFICIENCY; EXCITATION; Femtosecond pulses; GALLIUM ARSENIDES; HETEROJUNCTIONS; Heterostructures; LAYERS; Multilayers; PHOTOLUMINESCENCE; Photonics; Polaritons; POLARONS; PULSED IRRADIATION; State of the art; VISIBLE RADIATION; WAVELENGTHS
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4921586

We present a microcavity structure with a shifted photonic stop-band to enable efficient non-resonant injection of a polariton condensate with spectrally broad femtosecond pulses. The concept is demonstrated theoretically and confirmed experimentally for a planar GaAs/AlGaAs multilayer heterostructure pumped with ultrashort near-infrared pulses while photoluminescence is collected to monitor the optically injected polariton density. As the excitation wavelength is scanned, a regime of polariton condensation can be reached in our structure at a consistently lower fluence threshold than in a state-of-the-art conventional microcavity. Our microcavity design improves the polariton injection efficiency by a factor of 4, as compared to a conventional microcavity design, when broad excitation pulses are centered at a wavelength of λ = 740 nm. Most remarkably, this improvement factor reaches 270 when the excitation wavelength is centered at 750 nm.