All-Optical Logic Gates Based On SOAs And Filters

All-optical logic gates, as the key component of all-optical networks and the base of photonic computers, have received much attention in recent years. Semiconductor optical amplifier (SOA) is a strong candidate to realize all-optical logic gates due to its low power consume, small size and low response time. Theoretical and experimental researches on all-optical logic gates based on SOAs and filters are presented in this thesis, supported by the Science Fund for Distinguished Young Scholars of Hubei Province (Grant No. 2006ABB017) and the Program for the New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-04-0715). The main contents are listed as follows:(1) The research background and achievements of all-optical logic gates based on SOAs are clarified.(2) High-speed nonlinearities of SOA and ultrafast nonlinearities of SOA are clarified. SOA high-speed dynamic model for normal pulses and SOA ultrafast dynamic model for ultrafast pulses are presented respectively.(3) All-optical logic gates based on SOA and narrow bandpass filter is researched. The principle of operation is simulated using the SOA ultrafast dynamic model, and extension research is presented.(4) Improvements for all-optical logic AND gate based on cascaded SOAs are presented. The methods of adding fiber delayed interferometer and narrow bandpass filter after the first stage are simulated respectively. The operation of second stage is analyzed and discussed. All-optical AND gates for both return-to-zero (RZ) signals and non return-to-zero (NRZ) signals at 20Gb/s are demonstrated experimentally. The results at 40Gb/s are analyzed.