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arXiv · 2505.09695

Deterministic and highly indistinguishable single photons in the telecom C-band

Nico Hauser·Matthias Bayerbach·Jochen Kaupp·Yorick Reum·Giora Peniakov·Johannes Michl·Martin Kamp·Tobias Huber-Loyola·Andreas T. Pfenning·Sven Höfling·Stefanie Barz
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Abstract

Quantum dots are promising candidates for deterministic single-photon sources, yet achieving high photon indistinguishability at telecom wavelengths remains a critical challenge. Here, we report a quantum dot-based single-photon source operating in the telecommunications C-band that achieves a raw two-photon interference visibility of up to (91.7+-0.2)%, thus setting a new benchmark for indistinguishability in this spectral range. The device consists of an indium arsenide (InAs) quantum dot embedded within indium aluminum gallium arsenide (InAlGaAs) and integrated into a circular Bragg grating resonator. We explore multiple optical excitation schemes to optimize coherence and source performance. To our knowledge, this is the first demonstration of two-photon interference visibility exceeding 90% from a quantum-dot emitter in the telecommunications C-band, advancing the viability of solid-state sources for quantum communication and photonic networks.

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Nico Hauser, Matthias Bayerbach, Jochen Kaupp, Yorick Reum, Giora Peniakov, Johannes Michl, Martin Kamp, Tobias Huber-Loyola, Andreas T. Pfenning, Sven Höfling, Stefanie Barz. 2025-05-14. Deterministic and highly indistinguishable single photons in the telecom C-band. https://arxiv.org/abs/2505.09695

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