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提出了一种可实现非接触、远距离、高灵敏度的激光多普勒语音检测系统。该系统采用压电陶瓷(PZT)对迈克尔逊干涉仪的参考信号进行调制,利用相位产生载波法(PGC)对干涉信号解调,提高了零差干涉法的抗干扰性,并且具有光路简单、成本低等优点。推导了干涉信号的解析表达式,数值分析了PGC解调参数的最优值。实验结果表明:该系统能动态测量音频范围内的微弱振动,可较好地还原语音信号。
A laser Doppler speech detection system which can realize non-contact, long distance and high sensitivity is proposed. The system uses the piezoelectric ceramic (PZT) to modulate the reference signal of the Michelson interferometer, demodulates the interference signal by using the phase-generating carrier (PGC) method, improves the interference immunity of homodyne interferometry, and has the advantages of simple optical path, Low cost and so on. The analytical expression of the interference signal is deduced and the optimal value of PGC demodulation parameter is analyzed numerically. The experimental results show that the system can dynamically measure the weak vibration in the audio range and restore the speech signal well.