All-optical UWB impulse generation based on cross-phase modulation and frequency discrimination

All-optical ultra-wideband (UWB) impulse generation based on optical cross-phase modulation (XPM) and frequency discrimination is proposed and experimentally demonstrated. In the proposed configuration, an optical pulse train from a femtosecond pulse laser that is spectrum sliced to get the required pulse width is used as a pump, which is then injected into a nonlinear fibre together with a continuous-wave (CW) probe to create XPM. A fibre Bragg grating (FBG) is used as a frequency discriminator. By locating the cross-phase-modulated probe at the linear or the quadrature slopes of the FBG reflection spectrum, UWB monocycle or doublet pulses are generated.