A Novel Composite Method for Ultra-Wideband Doublet Pulses Generation

A novel composite approach to generate ultra-wideband (UWB) doublet pulses in optical domain through an electrical Gaussian pulse is proposed and demonstrated in this letter. Two pulses with reversed polarity generated by polarization modulation are fed into a differential group delay device and a semiconductor optical amplifier (SOA) wherein the optical pulse profile is modified. Doublet pulses are obtained after optical-electrical detection due to gain saturation and recovery mechanism in the SOA. The fractional bandwidth of doublet pulses exceeds 180%, fulfilling the UWB requirements.