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

In this work we explore monolithic optoelectronic 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 1GHz. The improved noise performance is leveraged against increased secure key rates and achievable reach in continuous-variable quantum key distribution (CVQKD).