基于增益开关激光器和高非线性光纤(HNLF),对产生超连续(SC)谱的方案进行了实验研究。验证了采用不同输入功率以及不同非线性系数的光纤对SC光源输出频谱的影响。针对频谱编码光码多分址(OCDMA)系统应用,提出了衡量SC光源性能的平坦度指标定义,即为C波段内除种子尖峰外的最大功率与最小功率的差值。针对采用HNLF不易产生SC光源,提出采用具有幅度均衡功能的波长选择开关(WSS)对SC光源的平坦度指标进行优化,平坦度从9dB降至3dB。将上述SC光源应用于动态可重构频谱编码OCDMA系统中,实现了40km的传输实验,误码率(BER)优于10^-9。
Supercontinuum(SC)light source is one of coherent wide spectrum light sources,because of the wide and flat spectrum,the high power density spectrum and the stability.This paper performs a further experimental research on the generation of supercontinuum based on the high nonlinear optical fiber(HNLF)and distributed feed back laser diode which works in the gain switch state.The experimental results demonstrate that the input power and nonlinear coefficient of HNLF both have an impact on the spectrum properties of SC source.As for the application of OCDMA in spectrum,the paper proposes the flatness,a difference between maximum power and minimum power,to quantify the planarity of SC source.At the same time,this paper chooses wavelength selective switch,which has a function of amplitude equalization,to optimize the flatness,and the flatness declines to 3dB.The SC source can be applied in dynamic reconfigurable spectrum coding OCDMA system to realize the experiment of 40 km transmission,and the error bit rate of the experiment can be less than 10^-9.