Research On Key Techniques Of All-optical Logic Gates And Visible Light Communication

With the rapid development of Internet and multimedia technology, as well as the explosion of network data traffic, the focus of information transmission business is the data, image, multimedia IP access and smart business and value-added service represented by high-speed data services, is no longer the traditional voice business. The surge of network traffic and increasing transport rate, proposes a big challenge for optical communication technology. Due to the "electronic bottleneck" restrictions,in current, optical networks relies on the use of higher-order modulation format to improve the signal transmission rate. However, this still cannot meet the demand for high speed, large capacity optical communication network. To break through this challenge, All Optical Network (AON) arises at the historic moment in which network transmission can be completed without optical-electric transformation and electrical-optical transformation.With the diversification of application scenarios, the visible light communication, because of its no electromagnetic interference, quickly becomes an important communication mode in the electromagnetic sensitive situations, such as plane and hospital, becoming a research hotspot in the field of communications. This article revolves around the two hot issues, the in-depth research and analysis have been done center on the all-optical logic gate with high speed and visible light communication which has many advantages like low cost, green non-polluting, high secrecy. The concrete research content is as follows:(1) This paper discusses the three kinds of all optical logic gates implementation schemes, analyzes and compares the advantages and disadvantages of the scheme. On this basis, we put forward the implementation scheme of all-optical logic gate based on In-phase/Quadrature Modulator (I/QM). The advantages of the scheme are high rate, reconfigurable, low complexity and low cost. Under the premise of without changing the hardware structure, we can achieve 24 kinds of basic logic gates just through adjusting parameters.(2) We analyze the mathematical model of imperfect I/Q modulator,based on which the theoretical performance analysis of the all-optical logic gates based on the I/Q modulator have been done, and through simulations we verify the effect of laser output power, insertion loss of modulator and extinction ratio on the performance of the system. The feasibility of the scheme is verified by the experiments.(3) The full duplex online system based on visible light communication using Light Emitting Diode (LED) was designed and implemented. Test results show that it still can realize stable Internet access at the data rate of 4 MB/s, transmission distance ?3m.