提出了一种DFB激光器传感信号解调方案。该方案以非平衡光纤Mach-Zehnder干涉仪为基本解调元件, 将DFB激光器波长的变化转换为干涉仪输出光强的变化, 并通过对干涉仪输出特性的分析, 设计了解调电路系统和偏振控制系统。解调电路系统在干涉仪可见度不为“0”的前提下, 输出信号不受可见度变化影响；偏振控制系统通过控制干涉仪输入光偏振态, 确保可见度远离“0”。该方案避免了干涉仪可见度波动对解调信号的影响, 获得对传感信号的线性输出。

A demodulation scheme for DFB laser sensing signals is proposed. The scheme uses an unbalance fiber Mach-Zehnder interferometer as the basic demodulation component, which can convert the change of the DFB laser wavelength into the change of the output intensity of the interferometer. By using the output characteristics of the interferometer, the demodulation circuit system and the polarization control system is designed. The output signal of demodulation circuit system is unaffected, when interferometer visibility is not zero. By using the polarization control system, the interferometer visibility is away from zero. The analysis show that by the scheme the linear output of the sensing signal is got.