Integrated Silicon Photonics for High-Speed Quantum Key Distribution

TL;DR

This paper demonstrates high-speed, low-error quantum key distribution modulation using integrated silicon photonics, combining slow thermo-optic and fast carrier-depletion techniques, advancing scalable quantum communication technologies.

Contribution

It introduces a novel integration of thermo-optic and carrier-depletion modulation in silicon photonics for high-speed quantum key distribution.

Findings

Achieved 10 GHz bandwidth modulation with low error rates.

Demonstrated compatibility with CMOS microelectronics.

Enabled scalable and integrated quantum communication devices.

Abstract

Integrated photonics offers great potential for quantum communication devices in terms of complexity, robustness and scalability. Silicon photonics in particular is a leading platform for quantum photonic technologies, with further benefits of miniaturisation, cost-effective device manufacture and compatibility with CMOS microelectronics. However, effective techniques for high-speed modulation of quantum states in standard silicon photonic platforms have been limited. Here we overcome this limitation and demonstrate high-speed low-error quantum key distribution modulation with silicon photonic devices combining slow thermo-optic DC biases and fast (10~GHz bandwidth) carrier-depletion modulation. The ability to scale up these integrated circuits and incorporate microelectronics opens the way to new and advanced integrated quantum communication technologies and larger adoption of quantum-secured communications.