水面声光耦合光纤水听器的抗波浪解调方法

为了减弱基于水面声光耦合的光纤水听器水面波动对解调信号造成的幅度衰落,采用了利用检测信号臂光强度信息补偿解调信号幅度的方法。从理论上推导了该方法修正解调信号的过程,并对该过程进行了数值仿真,同时实际搭建光纤水听器探测系统,利用/2相位解调法对水面恒定振动信号进行了实验验证。结果表明,相比原始解调信号,修正后的信号幅度基本稳定,幅度值整体提高5dB,解调信号失真度减小,相位噪声得到抑制,信噪比得到提高,可辨认信号时间长度扩展为原来的3.5倍。该方案能有效克服由水面波动引起的解调信号衰落现象,信号质量得到优化,系统抗波浪解调能力得到提高。

Anti-wave demodulation method for acousto-optic coupling fiber hydrophones on the water surface

A novel method was put forward to weaken the signal fading phenomenon of an acousto-optic coupling fiber optic hydrophone on the water surface when the water fluctuates. The method compensated the signal amplitude by detecting the light intensity of the signal arm. The amendment process of demodulation signal was analysed in theory and bynumerical simulation. A fiber optic hydrophone system based on /2 phase demodulation technique was constructed to test the water constant vibration signal. The results show that, compared with the original demodulation signal, the amplitude of the amended signal is stabilized and increased by 5dB wholly. The distortion degree is reduced, the phase noise is suppressed, the signal to noise ratio is improved and the time range of the identifiable signal is extended to 3.5 times. This method can overcome the signal fading phenomenon caused by surface fluctuation effectively, optimize the signal quality and enhance the ability of anti-wave demodulation for the system.