Study On The Upgrade And Uplink Re-modulation Of Passive Optical Networks

With the advent of full-service era, the bandwidth demand from users has been explosively increasing. How to upgrade the existing time-division-multiplexing passive optical network (TDM-PON) is a hot topic, we give two solutions:one is a novel evolution method for hybrid TDM/WDM-PON based on differential phase shift keying/not return-to-zero (DPSK/NRZ) orthogonal modulation, and its feasibility of seamless upgrade was verified through simulation and experimental demonstration; The other is an evolution method for next generation PON based on Radio-over-Fiber (RoF) technology, which can use baseband and frequency band for transmission, and enhance the network capacity gradually. Its feasibility is proven by theoretical analysis and system simulation.From the point of engineering, deploying colorless optical network unit (ONU) is convient for installation and maintenance in WDM-PON. Compared with other schemes for colorless ONU, uplink re-modulation shceme achieves the lowest cost, and WDM-PON is very sensitive to cost, so uplink re-modulation is a best choice to realize colorless ONU. A reflective semiconductor optical amplifier (RSOA) is a key device to achieve the uplink re-modulation scheme, which can realize the dual function of light amplification and modulation. In this paper in detail introduced the structure of RSOA, principle of re-modulation and parameters of RSOA used in the experiment. And its input and output characteristics and gain were tested.We also propose a novel data re-modulation scheme with downstream amplitude shift keying-differential phase shift keying (ASK-DPSK) signals and on-off keying (OOK) upstream signal using RSOA for WDM-PONs. It can highly increase network capacity and improve the optical power budget. Through technique principles, system implementation and experimental performance testing and analysis of the proposed scheme introduced in detail to verify its feasibility.