All-optical Signal Processing Technologies Based On SOA Nonlinearities In Optical Network

This dissertation mainly focuses on the subject of photonic technologies based on semiconductor optical amplifiers (SOAs) nonlinearities in optical network, including all-optical wavelength conversion, all-optical NRZ-to-RZ format conversion, all-optical logic NOR gate and OR gate. Several new schemes are presented and experimentally demonstrated for the first time or independently; corresponding theoretical models are built, and numerical analyses are conducted. The devices including wavelength converter, NRZ-to-RZ format converters, two logic NOR gates and logic OR gate have the advantages, including having simple configuration and allowing photonic integration and etc.1. Nonlinear polarization characteristic and theoretical model in SOAA theoretical model in relation to polarization is derived considering length effect of SOA. Based on the theoretical model, numerical analyses are conducted about polarization characteristics of gain, phase, spectrum and chirp in SOA.2. All-optical logic NOR and OR gate based on SOA nonlinearitiesTwo novel schemes are presented to realize logic NOR function. The first is by exploiting cross phase modulation and blue-shifted sideband filtering, here called XPM-BF scheme. The NOR gate is experimentally demonstrated at 40 Gbit/s with good extinction ratio and with clear open eye. The second scheme (NPR-BF) is by adding a polarization controller and a polarization beam splitter to XPM-BF scheme, here called NPR-BF scheme. The performance of logic NOR gate by exploiting NPR-BF can excel that by exploiting XPM-BF.Two theoretical models for logic NOR function are built by exploiting XPM-BF and NPR-BF considering polarization dependence in SOA. Numerical simulation are made for XPM-BF scheme, including the dependence of extinction on the input data power, offset of central wavelength of filter to input probe wavelength, phase modulation coefficient of SOA, 3dB bandwidth of filter and polarization angle of input linear polarization light. Numerical simulation are also made for NPR-BF scheme, including the dependence of extinction and Q factor on the input data power and offset of central wavelength of filter. A comparison is made among three schemes including XPM-BF, NPR and NPR-BF.A novel scheme is presented to realize logic OR function by exploiting nonlinear polarization rotation (NPR) and red-shifted sideband filtering, which is called NPR-RF. The logic OR gate is experimentally demonstrated at 20 Gbit/s.Two theoretical models to realize logic OR function are built by exploiting XPM-RF and NPR-RF considering polarization dependence in SOA. Numerical simulation is made for NPR-RF scheme, including the dependence of extinction and Q factor on the input data power, offset of central wavelength of filter to input probe wavelength. A comparison is made among two schemes between XPM-RF and NPR-RF.3. All-optical wavelength conversion and NRZ-to-RZ format conversion based on SOA nonlinearitiesA novel scheme is independently proposed to realize wavelength conversion by exploiting nonlinear polarization rotation (NPR) in SOA and red-shifted sideband filtering, which is called NPR-RF. The wavelength converter is experimentally demonstrated at 20Gbit/s and 40Gbit/s over up-conversion range 17 nm. The scheme can enhance the performance of conventional nonlinear polarization rotation. The simultaneous two wavelength conversion outputs are successfully obtained at 20 Gbit/s.A theoretical model for wavelength conversion is built by exploiting NPR-RF, considering polarization dependence in SOA. Based on Jones matrix, function of wavelength conversion is simulated by exploiting the scheme. Numerical simulation is also made for dependence of performance of the wavelength converter on the central wavelength offset of filter to input probe wavelength and input data signal power.A novel scheme is independently proposed to complete NRZ-to-RZ format conversion by exploiting nonlinear polarization rotation (NPR) in SOA. The format converter is experimentally demonstrated at 10Gbit/s. By adding red-shifted sideband filtering, the performance of format converter based on NPR is enhanced. Based on Jones matrix, function of format conversion is simulated to realize by exploiting two schemes considering polarization dependence in SOA.