In this paper, we first present a full numerical simulation for the trapping and retrieval procedure of eight continuing "1" Guassian pulses (i.e., "11111111") in the electromagnetically induced transparency (EIT) medium. This simulation shows that an EIT medium has the ability to store multiple light pulses in a shape-preserving way. And we also, for the first time, give the formula evaluating the maximum number of pulses that can be stored by an EIT medium at one time. This work reveals a new possible way to the reversible storage of the photonic information.

A five-node, eight-channel, wave-length division multiplexing (WDM) experimental all-optical network is present in China. The network has nodes of three 0ADMs and two OXCs, management function and self-healing function. Digital signal of 2.5 Gbit/s and analogue signals of CATV can be trans-mitted through and cross-connected. BER is less than 1.5

Three group velocity dispersion (GVD) compensation schemes, i.e., the post-compensation, pre- compensation and hybrid-compensation schemes, are discussed with considering polarization mode disper-sion (PMD). In the 10- and 40-Gbit/s non-return-zero (NRZ) on-off-key (0OK) systems, three physical factors, Kerr effect, GVD and PMD are considered. The numerical results show that, when the impact of PMD is taken into account, the GVD pre-compensation scheme performs best with more than 1 dB better of average eye-opening penalty (EOP) when input power is up to 10dBm in the 10-Gbit/s system. However the GVD post-compensation scheme performs best for the case of 40 Gbit/s with input power less than 13dBm, and GVD pre-compensation will be better if the input power increased beyond this range. The results are different from those already reported under the assumption that the impact of PMD is neglected. Therefore, the research in this paper provide a different insight into the system optimization when PMD. Kerr effect and GVD are considered.

Combining IP with WDM is an attractive direction for research. WDM will play an impor-tant role in IP network in future. Now, an urgent problem is how to introduce wavelength routing in an IP network. We solve this problem by designing IP wavelength router, implementing DPDP (default path and dedicated path) method. We prove the reasonableness and feasibility of this design by a prin-ciple experiment. A lot of problems related to this design are also discussed.

在光纤WDM通信系统或WDM网络，渡长控制是十分必要的，本文讨论了使用法布里一珀洛（FP）揩振腔作为波长控制器件，在考虑频道间串扰的情况下，波长控制的计算理论，对一频道间隔200GHz，16路信道，调制码率为2.488Gb/s的WDM系统的波长控制精度问题进行了计算和比较。