Research Of All-optical Buffer And Wavelength Conversion Based On Polarization Rotation In GT-SOA

All-optical networks can make the whole networks transparent for the optical signal, and improve the utilization rate of cyber source. The settlement of the conflict and the development of the all-optical networks will be accelerate if we combine all-optical buffer and wavelength converter. This thesis research the all-optical buffer and all-optical wavelength converter based on the polarization rotation in GT-SOA.We expound the SOA’s basic principle and make the simulation analysis in this thesis. We analyze the variance of carrier density in the SOA’s length, the gain’s change with signal power, and the influence of the pulse number and pulse rate to carrier density and light power.The all-optical buffer based on the polarization rotation in GT-SOA is analyzed, including the relationship between the buffer time and the length of the fiber loop, the influence of the phase shift between TE and TM mode on the polarization state, and the principle of this system. We simulate the variation of phase shift between TE and TM mode with the control light power and the injected current, and we simulate the difference of the polarization state by the Poincare sphere. At last we discuss the buffer-optical switch based on polarization rotation as the key component in the system.We propose an all optical 1310 to 1550nm wavelength conversion system based on nonlinear polarization rotation in GT-SOA which adds the assistant light to improve the property of the converted light. We analyze the influence of assistant light to carrier density, and we discuss the wavelength conversion and simulate the phase shift between TE and TM mode and the converted light for 20Gbit/s and 30Gbit/s signals. We analyze the influence of the input signal power, injected current and the assistant light power on the extinction ratio of the converted light.