Photonic monocycle pulse generation and modulation for ultra-wideband-over-fiber application

Abstract

In order to integrate local ultra-wideband (UWB) environment into fixed wired networks or wireless wide-area infrastructures and eliminate the high cost of microwave electrical circuits or devices, UWB-over-fiber systems have emerged to exploit the advantages offered by optical fiber. We experimentally demonstrate a photonic UWB monocycle pulse generation and pulse position modulation (PPM). The UWB monocycle pulse with inverse polarity can be generated based on the two differently-biased Mach-Zehnder modulators, subsequently the PPM of the UWB monocycle pulse is realized through the nonlinear polarization rotation (NPR) arising in a semiconductor optical amplifier (SOA). We proposed and experimentally demonstrated an effective procedure to generate and maintain a linear output state of polarization (SOP) during the course of the nonlinear polarization rotation (NPR) of an SOA. High performance of polarization switching can be achieved. The proposed scheme is more preferable for the UWB-over-fiber applications due to its compact size and high stability.