Nawrath, CorneliusJoos, RaphaelKolatschek, SaschaBauer, StephaniePruy, PascalHornung, FlorianFischer, JuliusHuang, JiashengVijayan, PonrajSittig, RobertJetter, MichaelPortalupi, Simone LucaMichler, Peter2024-06-202024-06-2020232511-90442511-9044189230788Xhttp://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-145779http://elib.uni-stuttgart.de/handle/11682/14577http://dx.doi.org/10.18419/opus-14558Several emission features mark semiconductor quantum dots as promising non-classical light sources for prospective quantum implementations. For long-distance transmission and Si-based on-chip processing, the possibility to match the telecom C-band is decisive, while source brightness and high single-photon purity are key features in virtually any quantum implementation. An InAs/InGaAs/GaAs quantum dot emitting in the telecom C-band coupled to a circular Bragg grating is presented here. This cavity structure stands out due to its high broadband collection efficiency and high attainable Purcell factors. Here, simultaneously high brightness with a fiber-coupled single-photon count rate of 13.9 MHz for an excitation repetition rate of 228 MHz (first-lens single-photon collection efficiency ≈17% for NA = 0.6), while maintaining a low multi-photon contribution of g(2)(0) = 0.0052 is demonstrated. Moreover, the compatibility with temperatures of up to 40 K attainable with compact cryo coolers, further underlines the suitability for out-of-the-lab implementations.eninfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by/4.0/620article2024-04-25