Monolithically Integrated Ultra-Low Noise Balanced Receiver for CV-QKD

TL;DR

This paper presents a monolithically integrated ultra-low noise balanced receiver designed for CV-QKD, achieving significant noise reduction and higher secure key rates compared to traditional heterogeneously integrated solutions.

Contribution

The work introduces a monolithic integration platform for low-noise balanced photodetectors, enhancing performance over heterogenous methods in CV-QKD systems.

Findings

Monolithic integration reduces input-referred noise significantly.

Achieved bandwidth above 1 GHz in the integrated receiver.

Enhanced secure key rates and reach in CV-QKD applications.

Abstract

In this work we explore monolithic opto-electronic integration platform for significant down-scaling of input-referred noise in custom designed low-noise analog front-end used for balanced photodetection. The performance of such monolithically integrated approach is compared to heterogeneously integrated solution designed in the same technology which requires wire-bonding to the balanced photodetectors. The designed circuits are targeting bandwidth above 1 GHz. The improved noise performance is leveraged against increased secure key rates and achievable reach in continuous-variable quantum key distribution (CV-QKD).