摘要
采用高相干窄带光源的光纤水听器时分复用(TDM)阵列中,信号光与其余通道的泄漏光之间不是简单的强度叠加,而是互相干涉。以此为基础,推导了8路TDM阵列中各通道光束相互作用的理论公式,得到了光开关的消光比是决定系统串扰的主要因素,最大串扰值约为消光比的一半的结论。信号解调采用相位载波解调(PGC),由于串扰频率分布广且远高于信号频率,提出了采样前先低通滤波的信号检测方案,该方案可滤除串扰高频成分,大大减小串扰频率混叠对PGC解调的影响。
In a TDM array using narrow band laser, the signal light and the light leaked from other channels don't add simply but interfere deeply each other. Based on this theory, the interference equations among different channels have been deduced and the result shows that the cross-talk mainly depends on the extinction ratio of optical switch, and the maximum cross-talk is nearly half of the extinction ratio. The demodulation of signal is performed based on PGC demodulation. As the frequency elements of cross-talk are wider and higher than the signal's, a measurement scheme with low filtering to filter the high frequency components before sampling is proposed in the paper, which can decrease the affection of frequency replication from cross-talk in the PGC demodulation.
出处
《光电工程》
EI
CAS
CSCD
北大核心
2005年第7期45-47,共3页
Opto-Electronic Engineering
