Research On All-optical Logic Device Based On Cross Gain Modulation Effect

All-optical signal processing will play a great role in future high-speed optical networks andoptical computing. The optical logic gates, as an important part of optical signal processing, havereceived much attention in recent years, and also are the crucial implements in packet switchingsystem, optical computing and optical transmission in future. Semiconductor optical amplifiershave many advantages such as small size, wide bandwidth and low response time, which makethem a strong candidate to realize all-optical logic gates. In this thesis, a novel scheme for anall-optical half subtractor based on cross gain modulation in SOAs is proposed. Theoretical researchon this subtractor is presented. The main contents are as follows:(1) The research background and significance of all-optical gates are introduced. Several kindsof all-optical logic gates based on the nonlinear effects in SOA and the domestic and abroaddevelopment are summarized.(2) The basic principle for SOA-based all-optical signal processing is investigated. Thepropagation equation for the optical field and the rate equation for the carrier density in SOA arederived. And the principle and applications for nonlinearities of SOA are discussed. Different SOAmodels and their applications are summarized.(3) The mathematical model used in the scheme is introduced. The static and dynamic gaincharacteristics of SOA are analyzed.(4) A novel scheme for an all-optical half subtractor based on XGM in SOAs is proposed. Thisall-optical half subtractor is theoretically realized by numerical simulation. And the influence ofinput pump power, the probe optical power and injection current of SOA on the properties, such asoutput power, are analyzed.