摘要
在２．５Ｇｂ／ｓ的光纤通信系统中，通常采用外调制技术以避免光源啁啾对传输距离的限制。这时系统传输特性的恶化主要来源于由光发射源静态谱线中的相位噪声经传输后转化而成的强度噪声（ＰＭ－ＡＭ噪声），以及光纤中的受激布里渊散射。文章通过将ＰＭ－ＡＭ噪声项引入Ｐｅｒｓｏｎｉｃｋ－ＣＣＩＴＴ误码率计算方法，从理论上研究了ＰＭ－ＡＭ噪声对系统传输特性的影响，并通过２．５Ｇｂ／ｓ３００ｋｍ传输实验的结果加以验证，同时也分析了系统中受激布里渊散射阈值与光源线宽的关系。所得的结果可为系统设计工作中综合考虑二者的影响提供一定的依据。
External modulators are widely used in the 2.5Gb/s optical communication systems to avoid the degradation due to laser chirp. In these systems, transmission power penalty is mainly caused by the phase modulation to amplitude modulation conversion noise and the stimulated Brillouin scattering in fiber. In this paper the power penalty induced by PM AM conversion noise is evaluated by calculating its power density spectrum at receiving end and using Personick CCITT BER calculating method. This paper also present experimental results of 2.5Gb/s 300km transmission to show the effects of the noise. Furthermore, the relationships between SBS threshold and laser linewidth in ASK modulating systems are analyzed. The work can be very helpful in designing high speed externally modulated systems by considering the transmission limitation set by both of the two effects.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
1998年第3期6-10,共5页
Journal of Tsinghua University(Science and Technology)
基金
国家"八六三"高技术项目
关键词
光纤通信
外调制
光源静态线宽
传输特性
optical communication
external modulation
laser CW linewidth
PM AM conversion noise
stimulated Brillouin scattering
