An adjustable amplitude and pulse-width laser modulation driver with active feedback for QKD experiments

摘要

This paper presents a laser modulation driver using active feedback in a 130-nm CMOS process. The driver is designed for laser modulator in quantum key distribution (QKD) experiments. The laser modulator requires a drive signal with adjustable amplitude and pulse-width. We employ a delay-adjustable delay chain and a multi-stage amplifier with active feedback to provide a current pulse signal with an adjustable pulse-width from 110 ps to 3.3 ns and an amplitude adjustment range of 0 mA to 14.4 mA to drive the laser modulation. By employing the active feedback, the rising/falling edge of the output current in the proposed circuit can reach 70 ps, while the data rate is up to 625 Mb/s. The post layout simulation results indicate that the modulation driver can meet the requirements of the QKD experiments.