The combination of semiconductor quantum dots (QDs) with photonic cavities is a promising way to realize non-classical light sources with state-of-the-art performances in terms of brightness, indistinguishability and repetition rate. In the present work we demonstrate the coupling of an InGaAs/GaAs QDs emitting in the telecom O-band to a circular Bragg grating cavity. We demonstrate a broadband geometric extraction efficiency enhancement by investigating two emission lines under above-band excitation, inside and detuned from the cavity mode, respectively. In the first case, a Purcell enhancement of 4 is attained. For the latter case, an end-to-end brightness of 1.4% with a brightness at the first lens of 23% is achieved. Using p-shell pumping, a combination of high count rate with pure single-photon emission (g(2)(0) = 0.01 in saturation) is achieved. Finally a good single-photon purity (g(2)(0) = 0.13) together with a high detector count rate of 191kcps is demonstrated for a temperature of up to 77K.
@article{arxiv.2107.03316,
title = {Bright Purcell enhanced single-photon source in the telecom O-band based on a quantum dot in a circular Bragg grating},
author = {Sascha Kolatschek and Cornelius Nawrath and Stephanie Bauer and Jiasheng Huang and Julius Fischer and Robert Sittig and Michael Jetter and Simone L. Portalupi and Peter Michler},
journal= {arXiv preprint arXiv:2107.03316},
year = {2021}
}