Quantum dot spontaneous emission control in a ridge waveguide
GÉRARD, Jean-Michel
Institut Nanosciences et Cryogénie [INAC]
Nanophysique et Semiconducteurs [NPSC]
< Réduire
Institut Nanosciences et Cryogénie [INAC]
Nanophysique et Semiconducteurs [NPSC]
Langue
en
Article de revue
Ce document a été publié dans
Applied Physics Letters. 2015, vol. 106, p. 41112 - 121108
American Institute of Physics
Résumé en anglais
We investigate the spontaneous emission (SE) of self-assembled InAs quantum dots (QDs) embedded in GaAs ridge waveguides that lay on a low index substrate. In thin enough waveguides, the coupling to the fundamental guided ...Lire la suite >
We investigate the spontaneous emission (SE) of self-assembled InAs quantum dots (QDs) embedded in GaAs ridge waveguides that lay on a low index substrate. In thin enough waveguides, the coupling to the fundamental guided mode is vanishingly small. A pronounced anisotropy in the coupling to non-guided modes is then directly evidenced by normal-incidence photoluminescence polarization measurements. In this regime, a measurement of the QD decay rate reveals a SE inhibition by a factor up to 4. In larger wires, which ensure an optimal transverse confinement of the fundamental guided mode, the decay rate approaches the bulk value. Building on the good agreement with theoretical predictions, we infer from calculations the fraction β of SE coupled to the fundamental guided mode for some important QD excitonic complexes. For a charged exciton (isotropic in plane optical dipole), β reaches 0.61 at maximum for an on-axis QD. In the case of a purely transverse linear optical dipole, β increases up to 0.91. This optimal configuration is achievable through the selective excitation of one of the bright neutral excitons.< Réduire
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