All-optical Multicast Based On Four-wave Mixing Of Semiconductor Optical Amplifiers

As the information age coming, the people’s demand for information is growing faster and faster. In order to meet the needs of the people, the current optical fiber communications is developing toward the direction of large-capacity and high-speed. To achieve the goals, the signal processing speed of network nodes should match the transmission speed in the fiber. As the "electronic bottleneck" exists, the conventional optical- electrical- optical signal processing is difficult to achieve high speed. And then, the future optical fiber communications—all-optical network which can directly process signal in the optical domain is proposed. And all-optical multicast technology is an important part of all-optical networks. It can improve the flexibility of the network and make better use of network resources. All-optical multicast technology is also an important means to resolve the problem of "electronic bottleneck", so the research for the all-optical multicast technology is absolutely necessary.In this thesis, the status and trends of the development of optical fiber communication is presented. The types of all-optical multicast technology, the principle of operation, the status and direction of development at home and abroad are reviewed. The all-optical multicast in semiconductor optical amplifiers based on four-wave mixing may be the tendency of the future all-optical multicast. A theoretical model of semiconductor optical amplifiers and the model of four-wave mixing in the semiconductor optical amplifier are built up. The all-optical multicast based on four-wave mixing of semiconductor optical amplifiers is investigated and discussed in detail.Main content of the thesis is as below:1. The basic theory of semiconductor optical amplifiers is studied, The basic equations of semiconductor optical amplifier coupled equations are derived. And based on these basis, a theoretical model four-wave mixing of semiconductor optical amplifier is developed.2. The simulation based on all-optical multicast based on four-wave mixing of semiconductor optical amplifiers is studied. The relationships between various factors and the conversion efficiency of all-optical multicast based on four-wave mixing of semiconductor optical amplifiers are achieved, which can be the reference for the later experiments.3. The experiment of all-optical multicast based on four-wave mixing of semiconductor optical amplifiers is achieved. The relationships between various factors and the conversion efficiency which achieved by the simulation are verified through the experiment, And the converted signal’s eye diagram and BER are tested. The various factors that affect the signal quality is ploted.4. Problem and solutions for the low conversion efficiency of all-optical multicast based on four-wave mixing of semiconductor optical amplifiers are analyzed. The scheme of injecting short-wavelength light to improve the conversion efficiency is realized by the simulation. A new plan of all-optical multicast using cascaded SOAs based on four-wave mixing of semiconductor optical amplifiers is proposed. Enable the multicast signals’ conversion efficiency have an average rise of 3-4dB, and the quality of multicast signals are greatly improved, the power penalty is reduced.5. Thesis work is summarized, and the future of all-optical multicast based on four-wave mixing of semiconductor optical amplifiers is prospected, and a further research program is developed.