The Simulation of Optical IR-UWB Doublet Pulse Generation and Fiber Transmission

We propose and simulate a novel scheme to generate an optical impulse radio ultra-wideband (IR-UWB) doublet pulse. The proposed scheme uses the gain saturation of a semiconductor optical amplifier (SOA) together with an optical delay line (ODL) to produce a second-order differentiator of Gaussian pulse, which is equivalent to a doublet pulse. The simulated results show that the generated IR-UWB doublet pulse has narrow spectral width which can comply with the Federal Communications Commission spectral requirements. Furthermore, we perform an investigation of a high speed IR-UWB over fiber system using on-off keying modulation (OOK), bi-phase modulation (BPM) and pulse-amplitude modulation (PAM) schemes. For the three modulation formats, the simulated results show that the IR-UWB doublet signal with the BPM modulation has better transmission performance and the power penalty of transmission over 20km single-mode fiber (SMF) is less than 0.2dB.