All Optical Buffer Based On Polorization Rotation Effect In Eam

All-optical network will be the development trend of modern communication network. In all-optical network, optical switching is the key component. All-optical buffer is the core in optical switching system. Through the buffering and processing of the data in optical level, all-optical buffer can effectively improve throughput at switching nodes.All-optical buffer solutions have been reported, but there is not all-optical buffer based on electro-absorption modulator (EAM) yet. A novel all-optical buffer based on polarization rotation effect of EAM has been proposed in this thesis.In the thesis, the fundamental theory of EAM is described as well as the basic absorption effects. Some basic indexes characterized the performance of EAM are explained. Carrier concentration equation is given. Based on that, the phase difference between TE and TM mode of signal light in the EAM is analyzed. Besides, a theoretical model on phase difference in EAM is established.Based on the theoretical model, the absorption coefficients of signal light are simulated and analyzed. According to the Kramer-Kronig constraint, the relationship between the refractive index of TE and TM mode and wavelength is revealed. Then the phase difference of two polarization mode with the pump light in EAM has calculated. At last, the influence of signal light and initial free carrier concentration in EAM on phase difference is presented.A novel all-optical buffer based on the polarization rotation principle in EAM is proposed and the feasibility of the design is analyzed.