本文介绍了一种新型LD/EA驱动器。该驱动器采用四个塑封NPN多晶硅双极晶体管和一个常规硅双极晶体管作为有源器件，可以在25n负载上产生50mA的调制电流用于直接驱动激光器或在50n负载上产生2.5V的调制电压用于驱动EA调制器。该驱动器的工作速率为DC至3Gb/s，调制电流和偏置电流涮节范围分别为5～50mA，上升、下降时间小于lOOps。

作者采用D-FF触发器、鉴相器和VCO构成的锁相环，研制出了码率为10.709Gbit/s的时钟数据再生模块。该模块的中心工作码率可在9.5-11Gbit/s之间设定，锁定带宽110MHz，输入信号幅度80-1600mV，输出信号幅度VINp-p 900mV，输出信号抖动均方根值JD-RMS=1.5-1.6ps、抖动峰峰值JD-p-p=7-8ps。

本文介绍了一种宽带机调Gunn振荡器。该振荡器结构简单可靠，单只振荡器就几乎可覆盖整个w波段，振荡器的最大括出功率可达25mw，在所有各频率点上的电调带宽约为450MHz。

mited range wavelength conversion. Eased on the results obtained, we conclude that the proposed analytical modells simple andyet caneffectively analyze the impact of wavelength conversion ranges and number of fibers onnetwork perfomlance. Also a new hmtristic approach for placement of wavelength converters to reduce blocking probabilities is explored Finally, we analyze network peffomlance with the proposed scheme. It can be observed from numerical simulations that limited range converters placed at a few nodes can provide ahilost the same blocking probability as full range wavelength converters placed at all the nodes. We also show that being equipped with amulti-fiberper-link has the same effect as being equipped with the capability of limited range wavelength conversion. So a multi-fiber per-link network using limited range wavelength conversionhas similar blocking peffomlance as a full wavelength convertible network Since amulti-fiber network using limited range wavelength conversion couldusefewer convertersthan a single-fiber network using limited range wavelength conversion and because wavelength converters are today more expensive than fiber equipment, a multi-fiber network in condition with limited range wavelength conversion is less cosfly than a single fiber network using only hiltited range wavelength conversion. Thus, multi-fiber per-link network using limited range wavelength conversion is currently a more practical method for all optical WDM networks. Simulation studies carried out on a14-nodeNSFNET, a10-node CERNET (China Education and Research Network)，and a 9-node regular mesh network validate the analysis.

We propose a new optical compensator for both first-order and higher-order polarization mode dispersion PMD effects in an optical fiber channel. The compensation scheme needs just one more polarization controller and one more variable differential group delay DGD element than first-order optical compensators with adjustable DGD elements. And the control algorithm for this compensator is easier and more stable than that for the typical higher-order optical polarization mode dispersion compensators. By an advised control method, the proposed compensator can always have better performance than first-order optical compensators. Numerical results are given to prove the efficiency of the proposed compensation scheme.