Research On Key Technologies For All-Optical Buffer

In future high-speed optical networks, it is crucial to develop all-optical signal processing to avoid the limits of electronic bottlenecks. The all-optical buffers, as important components of optical signal processing, have received much attention in recent years. There are several schemes for all-optical buffers. The all-optical buffers composed of OTF(optical threshold function) and wavelength converter are of great research value. SOA fiber ring lasers and micro-ring resonator can be used for OTF. Supported by the New Century Project for Excellent Talent of Ministry of Education (NCET-04-0715), the Excellent Youth Foundation of Hubei Province(2006ABB017), theoretical and experimental researches on OTF based on SOA fiber ring lasers are presented in this paper. Theoretical researches on micro-ring resonators are also presented. The main contents are listed as follows:(1) The research background, applications and achievements of all-optical buffers and micro-ring resonators are clarified.(2) Based on the carrier density rate equation, optical power propagation equation and sectional model of SOA, the dynamic characteristics of SOA are theoretically simulated. The theoretical models of SOA fiber ring laser are presented. Numerical calculations of SOA fiber ring laser at 10Gbit/s are given.(3) A scheme for all-optical buffer based on optical threshold function which is formed by two SOA fiber ring lasers is proposed. Numerical calculation and experimental evidence of optical threshold function's dynamic output at 10Gbit/s are given. The experiment results are in agreement with the calculation results.(4) The characteristics and principles of semiconductor micro-ring resonators are presented. The enhanced nonlinear responses in micro-ring resonators are analyzed in detail. Based on the two-photon absorption propagation equations, we simulate the applications of micro-ring resonators for all optical signal processing: filters, all-optical switches, wavelength conversions, all-optical logic gates.