Analytical Expression of the Threshold Pump Power of Erbium－doped Fiber Lasers Pumped at 980nm and 1480nm Wavelengths

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光纤通信技术的发展趋势

本文从ＥＤＦＡ，光复接分接，光同步，ＯＸＣ／ＯＡＤＭ等全光处理，ＷＤＭ，ＯＴＤＭ，光孤子等高在容量传输，ＮＺ－ＤＳＦ，ＰＩＣ／ＯＥＩＣ等光部件几个方面介绍光纤通信技术的发展趋势。     

光孤子通信原理与进展

当光纤中的色散与非线性效应平衡相消时,其中传输的光脉冲便可形成光孤子。利用光孤子传输长久不变形的原理,构成一种超高速、超长距离的光纤通信系统——光孤子通信系统。本文较为详细地阐明了这种新颖通信模式的基本原理与组成,以及有关设计上的一些考虑。在叙述中还对光孤子通信的近期发展情况作了若干评述。     

Different temporal patterns of vector soliton bunching induced by polarization-dependent saturable absorber

A fiber laser with either a polarization-independent semiconductor saturable absorption mirror (PID-SESAM) or a polarization-dependent SESAM (PD-SESAM) as a passive mode-locker is constructed for obtaining the vector soliton bunching. The temporal patterns of the soliton bunching generated from the fiber laser with a PD-SESAM are much more abundant than that in fiber laser with a PID-SESAM. Only the vibrating soliton bunching is generated from the fiber laser with a PID-SESAM. However, there are another three interesting temporal patterns of the soliton bunching generated from the fiber laser with a PD-SESAM except for the vibrating soliton bunching. They are variable length soliton bunching, breathing soliton bunching and stable soliton bunching along the slow axis induced by polarization instability. It is found that the polarization property of the saturable absorber plays a pivotal role for achieving different temporal patterns of the soliton bunching.     

OTDM高速孤子传输系统的稳定性研究

该文首次在同时考虑3种高阶效应和孤子互作用的条件下,应用变分法,导出了孤子各特性参数随传输距离的演化方程,基于此方程应用线性扰动法,从理论上导出了稳定性条件,论证了160 Gb/s高斯准孤子系统零频移稳定传输的可行性,并设计出一个比特率为160 Gb/s高速长距离孤子通信系统,对其性能进行数值模拟仿真,其结果和理论分析一致。     

光通信新动向

光通信在２０世纪为扩大网络传输容量起到了巨大的作用，在２１世纪将把通信网从电到光推向更高的台阶。本文对最近光通信领域的发展动向进行了归纳和总结，涉及到城域ＤＷＤＭ、ＯＣ－７６８Ｓｏｎｅｔ、光交换、光孤子、无源光网、可调谐激光器、光域业务互连、甚短距光设备和自由空间光网系统等九个方面。     

Effect of Soliton Propagation in Fiber Amplifiers

The propagation of optical solitons in fiber amplifiers is discussed by considering a model that includes linear high order dispersion, two-photon absorption, nonlinear high-order dispersion, self-induced Ramam and five-order nonlinear effects.Based on traveling wave method, the solutions of the nonlinear Schrodinger equations, and the influence on soliton propagation as well as high-order effect in the fiber amplifier are discussed in detail.It is found that because of existing five-order nonlinear effect ,the solution is not of secant hyperbola type, but shows high gain state of the fiber amplifier which is very favourable to the propagation of solitons.     

光时分复用光纤传输技术

光时分复用技术是实现超大容量传输的最有希望的途径之一。相对于日趋成熟的波分复用技术，ＯＴＤＭ技术正面临机遇与挑战。本文综述了光时分复用技术的特点，关键技术，研究现状，发展趋势和应用前景。     

光纤放大和光孤子长途通信

本文简述十余年来光纤通信从常规系统进化至新型系统所经历的过程,传输容量Gb/s·km以每四年增大十倍的速率前进。文中着重说明长途单模光纤线路中间装置掺铒光纤放大器,实现全光传输,不用再生中继机,每一光纤放大器在0.98μm或1.48μm激光管功率的抽引下,对1.55μm信号提供增益30dB。用12个光纤放大器,可使数字速率2Gb/s传输1000km成为实用的长途通信系统。最近实验室报道表明有可能使传输容量加大至50 000Gb/s·km。文中还介绍了光孤子通信实验的进展,在设置光纤放大器的1000km光纤线路上,获得光纤似的长途通信系统,由于光纤非线性抵消了色散效应,很窄的脉冲以很高的数字速率经过越长距离的传播,仍不呈现显著的脉冲展宽,和畸变及噪声影响。这种系统对越洲的陆地线路和越洋海底光缆极为有利。     

光纤中五阶非线性极化效应对黑脉冲传输的影响

考虑到光纤折射率的五阶非线性极化效应，本文对不同初始条件下，光纤中黑脉冲的传输进行了数值模拟分析，结果表明，高阶非线性极化效应对黑脉冲的分裂具有推迟作用。