Integrated InP-based transmitter for Continuous-Variable Quantum Key Distribution

TL;DR

This paper presents the design, fabrication, and testing of an InP-based integrated transmitter for continuous-variable quantum key distribution, demonstrating its potential for compact, efficient quantum communication systems.

Contribution

It introduces a monolithic InP photonic integrated circuit transmitter specifically for CV-QKD, a novel integration approach for quantum communication.

Findings

Achieved a secret key rate of 78 kbps over 11 km fiber

Demonstrated compatibility of InP PICs with CV-QKD protocols

Validated the potential for integrated quantum communication systems

Abstract

Developing quantum key distribution (QKD) systems using monolithic photonic integrated circuits (PICs) can accelerate their adoption by a wide range of markets, thanks to the potential reduction in size, complexity of the overall system, power consumption, and production cost. In this work, we design, fabricate and characterize an InP-based PIC transmitter for continuous-variable (CV) QKD applications. In a proof-of-principle experiment implementing a pulsed Gaussian-modulated coherent state (GMCS) CV-QKD protocol over an optical fiber channel of 11 km, the system showed a performance compatible with a secret key rate of 78 kbps in the asymptotic regime. These results show the potential of InP technologies to integrate CV-QKD systems onto a monolithic platform.