一种高效的相位调制激光多普勒频移测量方法

An Efficient Method for Doppler Shift Measurement of Phase Modulation Laser

为了充分利用相位调制信号中的多普勒频移信息,将相位调制信号的直流和拍频分量中的鉴频参量相结合,构造出一个新的鉴频参量。在理论和实验上,通过依次比较表明新鉴频参量继承了相位调制拍频信号振幅多普勒频移测量方法的特点和优势,相比之下,测量动态范围约提高1倍,测量精度约提高6倍。为了有效利用闲置的回波信号光功率,提出了基于新鉴频参量的双边缘相位调制多普勒频移测量方法,在理论上证明其可将测量灵敏度提高1倍。

In order to make full use of the Doppler shift information in the phase-modulated signal,we combine the frequency-discriminating parameters in the direct current with beat components of the phase-modulated signal in sequence to construct a new frequency-discriminating parameter.It is proved theoretically and experimentally that the new frequency-discriminating parameter inherits the characteristics and advantages of amplitude-Doppler shift measurement of phase-modulated beating frequency signal.In comparison,the dynamic range is increased by about one times and the measuring accuracy is improved approximately by six times.In order to make use of the idle optical power of the echo signal,we propose a new dual-edge phase Doppler shift measurement method based on the new frequency-discriminating parameter.It is proved theoretically that the proposed method can double the measurement sensitivity.