强度调制／直接检测（IM／DD）光纤通信系统色散限制的研究

通过引入归一化脉宽Ｐ和相对脉冲展宽因子ｑ，提出了一个适用于ＩＭ／ＤＤ系统中各种眼图恶化量ｘ和归一化脉宽Ｐ的色散限制改进公式。通过与其它理论的比较、计算机仿真和对实验数据的分析，验证了该公式的正确性，并给出了其它结果的限制条件。研究表明：当眼图恶化量ｘ为１ｄＢ左右时，对２．５Ｇｂ／；外调制信号（α＝０）而言，非色散位移光纤ＩＭ／ＤＤ系统的色散因子γ约等于０．７９，所对应的系统再生中继距离约为９００余公里。

Andysis on Dispersion Limit for Intensity Modulation/Direct Detection(IM /DD)Optical Fiber Transmission Systems

With the introduction of norlt1alized pulse width P and relative pulse broadening factor q,an improvedformula on the dispersion limit of IM/DD optical fiber transmission systems is derived under arbitrary P andeye opening penalty X. The formula s correctness is verified by the comparison with published experimentaldata,computer simulation,as well as other theoretical analyses,and the constraints of existing theories aregiven, It is shown that the dispersion index Y of a 2. 5Gb/s external modulated signal with a=0 is around0.79,el1suring the achievement of near to l 000km non dispersion shifted fiber transmission withoutregeneration,with the eye open ing penaIty X being still less than l dB.