应用相敏光放大器的非零色散位移光纤通信系统中的 ISI限制距离研究

ISI LIMITATION FOR NON ZERO DISPERSION SHIFT FIBER TRANSMISSION SYSTEM USING IN-LINE PHASE-SENSITIVE AMPLIFIERS

本文分析了 1 .55μm信号波长 ,采用强度调制 /直接检测 ( IM/DD)方式的单信道级联相敏光放大器 ( PSA)非零色散位移光纤传输系统的性能 .应用非线性薛定谔方程 ( NL SE) ,通过对信号传输后眼图劣化度的计算 ,得到了光纤传输系统的码间干扰 ( ISI)限制距离 .由于PSA的相敏特性 ,其对光纤色散具有一定的补偿作用 ,因此级联相敏光放大器光纤通信系统可以实现信号高比特率长距离传输 .然而 ,随着信号速率的提高 ,对长距离传输 ,必须减小光纤色散值和 PSA的间距 .当光纤色散值大到一定程度 ,要进行信号的高速率传输 ,就必须附加其它的色散补偿方法 .

The performance of single channel,intensity modulation/direct detection (IM DD),in line optical phase sensitive amplifiers (PSA′s),non zero dispersion shift fiber transmission systems at 1.55μm signal wavelength is theoretically analyzed.ISI limit distance was numerically calculated by eye pattern degradation using the nonlinear Schro[DD(-7/8] ¨dinger equation (NLSE).We clarify that because of it′s phase sensitive property,PSA has certain compensation effect on dispersion of non zero dispersion shift fiber,hence high bit rate long distance transmission can be realized using cascaded in line PSA′s.But as bit rate getting higher,fiber dispersion and amplifier spacing must be kept smaller for long distance transmission,and when the dispersion of fiber is fairly large,other dispersion compensation techniques must be added for higher bit rate transmission.