Berlin 2024 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 27: Quantum Dots and Wires: Optics II
HL 27.1: Talk
Wednesday, March 20, 2024, 09:30–09:45, EW 202
Single mode coupled emission of resonant and cw excited GaAs quantum dots — •Martin Kernbach1, Sophia Fuchs2, Julian Siller2, and Andreas W. Schell1 — 1Johannes Kepler University Linz — 2Leibniz University Hannover
Advanced quantum technologies like computing or sensing demand for deterministic bright sources of single indistinguishable photons. In order to provide quantum light of isolated systems properly usable for quantum applications, an efficient excitation and extensive collection in a single mode is required. Single molecules and cavity confined quantum dots are convenient sources. The coupling to the excited state is maximized on resonance, but challenges the usability of the emitter due to the effort for separation of the optical excitation mode from the mode of emission. A temporal, spacial, spectral, or combined method for separation is typically used.
Here we present a realization of a single emitter under resonant excitation in a confocal setup with a polarization filtered emission coupled into a single mode fiber. The optical path is free beam along a one meter long stick which dives the objective lens and scanning stage into a liquid helium reservoir. For resonant cw excitation of GaAs semiconductor quantum dots a SNR of polarization suppression up to 400 and count rates of 2 Mcps are archived by using a collecting lens with NA 0.68 only. Under this scheme further investigations regarding the blinking behavior are possible as well as probing alternative emitters like single molecules.
Keywords: rabi oscillation; blinking dynamics; resonant excitation; single photon source; confocal microscopy