Study on adaptive dispersion equalization techniques in reconfigurable photonic netwoak

自适应均衡技术是高速光子网络可靠运行的关键技术之一。自适应均衡技术虽然在无线电通信领域有着悠久的历史，但在光子系统中的应用却刚刚起步。与无线电通信系统不同，光纤中的传输条件相对稳定，几乎不受环境条件的影响。然而，当比特率超过40Gbit/s时，传输性能对光纤特性（如损耗、色散等）的微小变化变得敏感。此外，在全光网络中，光路是根据业务需求动态分配的。由于连接光节点的光纤通常具有不同的光特性，因此随着光路的重新分配，传输条件会发生变化。因此，应将光纤通信系统视为“时变系统”。本研究的主要目的是发展自适应色散均衡技术，并为可重构光子网络的可靠运行提供指导。为了实现这一目标，我们将项目分为以下四个部分，并进行了理论和实验研究：(1)利用光调频方法研制高速色散监测器；(2)基于谱相位的光脉冲表征技术的发展及其在色散监测器中的应用；(3)动态光学元件色散的评价；(4)大容量超长距离传输系统色散监测和实时自适应色散补偿的演示。通过这些研究，我们指出了可重构网络在役色散监测和实时色散补偿中可能存在的问题，并提出了解决方案。我们相信这些结果为未来高速光子网络可靠运行的自适应色散补偿技术奠定了基础。少

Adaptive equalization technique is one of the key technologies for reliable operation of high-speed photonic networks. Although the adaptive equalization technique has a long history in the field of radio communication, its application to photonic systems has just begun recently. Unlike radio communication systems, the transmission condition in optical fibers is relatively stable and almost immune to environmental conditions. However, as the bit-rate increases over 40Gbit/s, the transmission performance becomes sensitive to a slight change in fiber characteristics such as loss, chromatic dispersion and so on. Furthermore, in all-optical networks, the optical path is dynamically assigned depending on traffic requirements. Since optical fibers which connects optical nodes usually have different optical characteristics, the transmission condition changes with re-assignment of optical path. In this way, optical fiber communication system should be treated as "time-varying system."The objec … More tive of this study is to develop adaptive dispersion equalization techniques and show the guideline for reliable operation of reconfigurable photonic networks. In order to achieve this objective, we divided out project into the following four part and carried out theoretical and experimental studies : (1)the development of the high-speed dispersion monitor by using optical frequency modulation method, (2)the development of the optical pulse characterization technique based on spectral phase and its application to the dispersion monitor, (3)the evaluation of the dispersion of dynamic optical components, and (4)demonstration of the dispersion monitoring and real-time adaptive dispersion compensation in large capacity, ultra long-haul transmission systems. Through these studies, we pointed out potential problems on in-service dispersion monitoring and real-time dispersion compensation in reconfigurable networks and offered their solutions. We believe that these results lay the foundations of the adaptive dispersion compensation techniques for the reliable operation of future high-speed photonic networks. Less