A novel approach is used to implement optical carrier suppression and separation （OCSS） labeling. Then, the performance of 10/40-Gb/s duobinary payload with 2.5-Gb/s amplitude shift keying （ASK） or duobi- nary label by numerical simulations is studied. Influencing factors, such as demultiplexer bandwidth and fiber Bragg grating （FBG） filter bandwidth, are investigated. Simulation result shows that the received sensitivity of ASK label is higher than that of the duobinary label, while the received sensitivity of duobi- nary payload with duobinary label is higher than that with ASK label.
A novel architecture for wavelength-division-multiplexing passive optical network （WDM-PON） with centralized light-wave is proposed and demonstrated. At the optical line terminal （OLT） session of this architecture, optical differential quadrature phase shift keying （DQPSK） modulated signal with constant-intensity at 10 Gbit/s is utilized for downstream transmission. At the optical network unit （ONU）, part of the downstream optical power is remodulated with on-off keying （OOK） intensity modulation at 10 Gbit/s for upstream without additional laser. Simulation results show that the power penalties of the downstream for 20 km single-mode fiber （SMF） transmission and multi-channels are negligible. While for the upstream, the power penalties are obvious. The simulation results and analysis also reflect that by reducing the launch power of DQPSK transmitters, power penalties can be reduced, although the transmission distance is limited.
ZHANG Wei-feng XIN Xiang-jun ZHANG Qi ZHANG Zi-xing NAI Wei SHI Yan
