posted on 2024-01-24, 01:06authored byDaniel
A. Vajner, Paweł Holewa, Emilia Zięba-Ostój, Maja Wasiluk, Martin von Helversen, Aurimas Sakanas, Alexander Huck, Kresten Yvind, Niels Gregersen, Anna Musiał, Marcin Syperek, Elizaveta Semenova, Tobias Heindel
Semiconductor quantum
dots (QDs) enable the generation of single
and entangled photons, which are useful for various applications in
photonic quantum technologies. Specifically for quantum communication
via fiber-optical networks, operation in the telecom C-band centered
around 1550 nm is ideal. The direct generation of QD-photons in this
spectral range with high quantum-optical quality, however, remained
challenging. Here, we demonstrate the coherent on-demand generation
of indistinguishable photons in the telecom C-band from single QD
devices consisting of InAs/InP QD-mesa structures heterogeneously
integrated with a metallic reflector on a silicon wafer. Using pulsed
two-photon resonant excitation of the biexciton–exciton radiative
cascade, we observe Rabi rotations up to pulse areas of 4π and
a high single-photon purity in terms of g(2)(0) = 0.005(1) and 0.015(1) for exciton and biexciton photons, respectively.
Applying two independent experimental methods, based on fitting Rabi
rotations in the emission intensity and performing photon cross-correlation
measurements, we consistently obtain preparation fidelities at the
π-pulse exceeding 80%. Finally, performing Hong–Ou–Mandel-type
two-photon interference experiments, we obtain a photon-indistinguishability
of the full photon wave packet of up to 35(3)%, representing a significant
advancement in the photon-indistinguishability of single photons emitted
directly in the telecom C-band.