Optical Generation and Distribution of UWB Signals (Invited Paper)

In this paper, we present two systems for the generation and distribution of ultrawideband (UWB) pulse signals in the optical domain. The first system consists of a single-wavelength laser source, an electrooptic phase modulator (EOPM), a length of single-mode fiber (SMF) and a photodetector (PD). The combination of the EOPM, the SMF link and the PD forms an all-optical microwave bandpass filter, which is used to generate Gaussian doublet pulses at the receiver front-end. In the second system, pulsed light is wavelength-converted to phase-modulated light via cross-phase modulation in a nonlinear fiber. A fiber Bragg grating (FBG) that serves as a frequency discriminator is connected at the output of the nonlinear fiber. By reflecting the phase- modulated light at the slopes of the FBG, electrical monocycle and doublet pulses are obtained at the output of the PD. Experimental results measured in both temporal and frequency domains are presented. The use of the second configuration to implement pulse on-off, polarity and shape modulations in the optical domain is also discussed, which provides the potential for fully exploiting the advantages provided by UWB-over-fiber networks