Study On All Optical Time Division Switching Technology Based On Optical Buffers

Synchronous time division is the mainstream of switching technology in large switching machine. Despite the fast developing of the current packed-based asynchronous switching technology, the synchronous digital program-controlled switches still occupied a certain scale in large exchange offices, for their huge exchange capacity. In the development of high-speed all-optical network, how to change the existing equipment all-optical, eliminating the need for the photoelectrical conversion is a very rewarding job. The optical buffer can accomplish the time division exchange operation of optical data avoiding optical-electrical-optical conversion process, overcoming the bottleneck of electron rates in communication network and will be a key component of the all optical synchronous time division switches in future. The optical buffer based on nonlinear polarization rotation in a semiconductor optical amplifier is a novel optical buffer, which has the advantages of easy integration and can be cascaded.In this thesis, with the supporting of the state863Project "optical packet switching ring based on the elasticity of the optical buffer" and the National Nature Science Foundation of Parallel digital cascade structure study of the optical buffer, researches were deployed on all optical switch and buffer base on nonlinear polarization rotation in semiconductor optical amplifiers. And on this basis, targeting all optical synchronous digital program-controlled switches, a systematic exploration of all-optical synchronous time division switching system was carried out.The main contributions of this dissertation are listed as follows:1. By the study of the relationship of injected current in SOA and the NPR effects, we got a high-performance SOA-based polarization switch, and the splitting ratio and extinction ratio can reach30dB, and also we proposed a new2×2optical switch based on NPR in SO As.2. Firstly proposed a delay device composed of all optical buffer based on NPR effect in SOA. With only one SOA in the buffer units, a simple compact structure integrated in all-optical buffer. Experimentally realized a2.5G data optical packet of127bit buffered40laps. The relationship of cache laps with the output power, and gives the power equalization solutions and experimental results by the way of PZT. 3. Realized the time slot interchange of triple data packets in buffer units based on NPR of SOA. The results illuminates this system performs well on the TSI operation between triple data packets, and the longest time gap is124ns. The safe distance of time gap exchanging was also studied and the distance is13ns. Built a four cascade cache structure. Based on this system, segmented cache experimental study of a single data package was performed, each cache unit buffer depth reached90%.4. For the first time, a time slot interchange system with a STS structure of buffer units based on NPR effect of SOA was realized and an experiment four packets complete time slot interchange was completed.5. Proposed a optical time division switch structure of4×4all-optical switching matrix for the first time. The cache part was a combination of parallel feedback caching unit with less expensive devices. Solve the node data conflict node signal integrity and consistency remains good. Because of the gain role of the SOA, this node with a certain degree of self-similarity shaping functions.