40 GHz optical PLL based on four-wave-mixing in a semiconductor optical amplifier

Abstract

A phase-locked loop circuit without a low-frequency reference oscillator is presented. The circuit is based on four-wave mixing in a semiconductor optical amplifier and a local-oscillator-free electronic feedback circuit. The prescaled 10 GHz clock signal was recovered from a 40 Gbps time-division-multiplexed optical signal which is multiplexed from a mode-locked erbium-doped fiber ring laser.