有光纤放大器的光纤调幅有线电视系统的非线性失真理论研究

Theoretical Study on Nonlinear Distortion in aLightwave AM CATV System with EDFA

本文从理论上研究了有掺铒光纤放大器的光纤调幅有线电视系统的非线性失真问题。提出了等效失真项的概念，并对６０个ＰＡＬ－Ｄ制频道的光纤调幅有线电视系统计算了等效二阶和等效三阶失真项分布。还推导出掺铒光纤放大器的增益斜率与光源调制频率啁啾相互作用产生的二阶和三阶非线性失真的表达式及其传播规律。对采用掺铒石英光纤放大器或掺铒氟光纤放大器二种情况下计算了系统的非线性失真，并相比较。

In this paper the nonlinear distortion in a lightwave AMVSB CATV system with erbiumdoped fiber amplifier(EDFA) was studied theoretically. The concept of effective distortion term was suggested and the distribution of effective 2nd and 3rd distortion terms in a 60channel PALD AM CATV system was evaluated. The distortion generated from interaction between the gain slope of EDFA and the DFB laser chirp was formulated. The distortion with erbiumdoped fluoride or silica fiber amplifier was calculated and a comparison between them was made.