Amplitude variations caused by fiber nonlinearity in photonics-assisted microwave signal replication

Abstract

—Photonics-assisted microwave signal replication based on fiber-recirculating loops has been applied to microwave detection and processing. But, in the fiber recirculating loops, optical signals are significantly influenced by the nonlinear optical effects. In this paper, we analyze the amplitude variations of the replicated microwave signals that are caused by fiber nonlinearity. Numeric simulations and experiments are implemented. Periodical amplitude fluctuations can be induced by modulation instability, in which the period of fluctuations depends on the optical power in the fiber loop. The experimental results agree with the simulation results, indicating that the fiber nonlinearity has significant effects on the amplitude and signal-to-noise ratio of the replicated microwave signals.