光纤光栅非线性时延对啁啾的电视信号的影响

Influence of Fiber Grating Nonlinear Delay on Chirped CATV Signals

分析了有线电视系统中 ,用作色散补偿的光纤光栅因色散抖动对信号载波互调比产生的影响 ,结果显示色散抖动对有线电视信号互调比的影响随抖动幅度、抖动周期、信道数目的增加而增加 ,信道频率的分布也对其有影响。对光栅的色散特性进行数值估算 ,发现常耦合系数线性啁啾光栅不能用的有线电视系统中进行色散补偿。

Fiber grating has good compensation ability with less loss, so that it can replace dispersion compensation fiber. when the period of dispersion ripple is much larger than the signal bandwidth, there is deviation of compensation ability for the grating. When such period is equal to or smaller than the signal bandwidth, there is interference between codes and the energy distribution in adjacent elements would be changed. The influence of dispersion ripple of fiber gratings on chirped CATV (cable television) signals carrier-to-intermodulation ratio (IM) was investigated. The value of IM is related to the amplitude and the period of dispersion ripple. The number and the distribution of channels have an effect on the IM value. It is found that the uniform linearly chirped grating can not be used in CATV systems.