40Gb/s(STM-2 5 6)高速时分复用传输技术前景展望

随着技术的发展 ,4 0 Gb/ s(STM- 2 5 6 )作为 10 Gb/ s(STM- 6 4)传输业务颗粒的后续者 ,开始逐渐为业界熟悉。就 4 0 Gb/ s这一新兴技术的市场推动因素、应用场合以及影响 4 0 Gb/ s传输的一些关键技术作了介绍 ,并对其将来的应用前景作出展望     

Analysis of Radio over Fiber system for mitigating four-wave mixing effect

In this paper, an efficient 8-channel 32Gbps RoF (Radio over Fiber) system incorporating Bessel Filter (8/32 RoF-BF) has been demonstrated to reduce the impact of non-linear transmission effects, specifically Four-Wave Mixing (FWM). The simulation results indicate that the proposed 8/32 RoF-BF system provides an optimum result w.r.t. channel spacing (75 GHz), input source power (0 dBm) and number of input channels (8). In comparison with the existing RoF system, the proposed 8/32 RoF-BF system has been validated analytically and it is found that the performance of the proposed system is in close proximity particularly in FWM sideband power reduction of the order of 4 dBm for the 8-channel 32Gbps RoF system.     

WDM光纤通信系统中PMD自动补偿的研究

文章提出采用粒子群优化算法,提取信号的偏振度(DOP)作为反馈信号来补偿多信道光纤通信系统中的偏振模色散(PMD).作为例子,对两信道的波分复用(WDM)系统中的PMD进行了自动补偿,并进行了数值模拟,得到了两个信道补偿前后的DOP以及眼图变化情况.模拟结果表明这种算法对补偿多个信道的PMD是有效的.     

螺旋线慢波结构色散特性与耦合阻抗测量系统误差分析

本文系作者研制的＂螺旋线慢波结构冷特性自动测量系统＂的补充,给出了此类系统测量误差的详细理论分析,并对典型数据进行了计算。结果表明色散特性（相光速比）的测量误差可小于0.5%,基波耦合阻抗的测量误差则可达15%。     

铁氧体-硅双层基片微带线的谱域导抗法分析

该文提出两种铁氧体-硅双层基片的微带线结构,并通过对麦克斯韦方程的坐标旋转和傅里叶变换导出波导纳,用谱域导抗法进行特性分析。尤其是对微带线的色散特性进行了计算,讨论了微带线各种参数对色散特性的影响,并对它们的特性进行了对比,发现其中一种结构的色散受各因素的影响很小,尤其是介质的工艺尺度,可用于更高集成电路的制造中。     

OPTICAL FIBER NONLINEAR SOLITON COMMUNICATION

In anormalous dispersion of monomode optical fiber,optical solitons are evolvedfrom optical pulses when the dispersion is balanced by the nonlinearity.Undistorted transmissioncan be realized by using optical solitons,which can offer much greater the transmission capacityand extend the repeater spacing of the fiber communication system.The mechanism of thegeneration of optical solitons is expounded.A few forms of nonlinear transmission equationare obtained by using a concise method.The general complete expression of elementary solitonsolution of the nonlinear transmission equation without loss is given,and the design of the solitontransmission system is discussed.     

多种物质的远红外吸收研究

根据散射理论,描述了多种物质对红外入射的吸收问题。首先通过计算单个粒子的有关参数,推导出了一定条件下气悬体粒子随参量变化时的透射关系,进而计算出一定入射波长条件下某些远红外材料的最低透射率,从绘制的透射率曲线看出,每个连续的透射率曲线都有一个最小值。显然,选择对应的粒子直径可以为烟幕加工提供理论上优化的依据。最后给出了实验结果。     

基于光子晶体光纤的色散补偿和色散平坦技术

本文介绍了在各种结构参数下光子晶体光纤的色散特性，总结了实现光子晶体色散补偿光纤和光子晶体色散平坦光纤的各种设计方法。利用光子晶体光纤结构设计的灵活性，可以设计出具有各种色散曲线的光子晶体光纤，而这些光纤大略可以分成两类：空气孔直径大小一致的普通光子晶体光纤和空气孔直径大小变化的光子晶体光纤。从数值仿真的结果来看，如果选择适当的空气孔分布结构，空气孔直径大小变化的光子晶体光纤可以具有非常优异的色散补偿和色散平坦特性。这些数值仿真为实际的光子晶体的制作提供了参考。     

光纤中的四波混频及其受色散的影响

讨论了四波混频的效率及色散对四波混频的影响，并推导了四波混频光的效率公式。另外，在光纤线路中由于每段光纤的零色散波长略有不同，四波混频的发生与有均匀零色散波长光纤中的不同，本文对这种情况下的四波混频也进行了分析研究。     

Performance Comparison of WDM Systems with Different Duty Cycle

The performances of nonlinear WDM systems with different duty cycle are compared by means of numerical simulation.The numerical results show that the optical pulse with duty cycle of 0.5 is superior to the conventional NRZ modulation schene.The conclusion is different from that of some references.The reason is that inter symbol interference is not included in some references.In fact,inter symbol interference plays an important role in monlinear WDM system.Although the larger the duty cycle is,the stronger the effect of the cross-phase modulation and self-phase modulation on nonlinear WDM is however,the larger the duty cycle is ,the stronger the inter symbol interference is.