UWB monocycle and doublet pulses generation in optical domain

A novel composite approach to generate UltraWidcBand (UWB) monocytic and doublet pulses in optical domain is proposed and demonstrated in this paper. Simple electrical Gaussian pulse is modulated on optical earlier to generate UWB monocycle and doublet pulse successively. The UWB monocytic pulse is first generated based on birefringence time delay in polarization-maintaining fiber (PMF). Two polarity-reverse pulses are generated by polarization modulation using a single phase modulator and delayed in PMF with proper time to generate monocycle pulse. Semiconductor optical amplifier (SOA) is placed after the monocytic pulse generation to modify the optical pulse profile. Thanks to the gain saturation and recovery in SOA, the doublet shape pulse can be obtained. The fractional bandwidths of monocycle and doublet pulses arc 140% and 160% respectively, which can meet the UWB requirements.