Generation and distribution of 1.25 Gb/s ultrawideband doublet pulses based on the combination of nonlinear polarization rotation and parametric amplification

We propose an alternative photonic scheme to generate a doublet ultrawideband (UWB) pulse, which is based on the combined use of nonlinear polarization rotation (NPR) and optical parametric amplification (OPA). The proposed scheme uses NPR together with OPA in a highly nonlinear dispersion-shifted fiber to produce an ideal transfer function with which input Gaussian pulses are successfully converted into doublet pulses. An experimental demonstration was carried out to verify the working principle. The system performance of the generated UWB doublet pulses was assessed by propagating them over a 20-km-long fiber link, followed by wireless transmission. Error-free transmission was successfully achieved at a data rate of 1.25 Gb/s.