All-optical binary phase-coded UWB signal generation using DWDM-based multi-channel frequency discriminator

A simple all-optical binary phase-coded ultra-wideband (UWB) signal generation scheme only using a DWDM-based multi-channel optical frequency discriminator is proposed and demonstrated. In the proposed scheme, the CW lights emitted from a laser array are modulated in a phase modulator driven by electrical Gaussian pulses, and then are sent to a DWDM used as a multi-channel optical frequency discriminator, in which phase modulation to intensity modulation (PM-IM) conversions are performed, and by locating the phase-modulated light wavelengths at the positive or negative slopes of the DWDM transmission spectra, delaying and recombining each channel signal, binary phase-coded UWB codes are generated. We numerically demonstrate encode and decode process of binary phase-coded UWB signals with a code length of 4, operating at 625 Mbit/s. In addition, binary phase-coded UWB signal transmission in fiber link was also numerically investigated. Our proposed system has potential application in future multi-user UWB-over-fiber communication systems.