Li Yangtaozi, Gao Hong, Zhao Liguo, Fu Zhipeng, Zhang Juan, Li Zhen, Qiao Xueguang
Appl Opt. 2022 Jul 1;61(19):5722-5727. doi: 10.1364/AO.459267.
In this paper, an improved phase generated carrier (PGC) demodulation algorithm based on frequency mixing and division difference is proposed. The effects of phase modulation depth variation and light intensity disturbance of the light source on the demodulated phase signal are investigated theoretically and experimentally. Compared to the traditional PGC differential-cross-multiplying (PGC-DCM) and PGC arctangent (PGC-Arctan) demodulation algorithms, the ameliorated demodulation algorithm eliminates the harmonic distortion of the demodulated signal by extracting the carrier modulation depth through frequency mixing. The demodulation error caused by the light intensity disturbance of the light source is suppressed by division difference. The stability of the demodulation system is improved. To verify the algorithm, a PGC demodulation system is built based on a Michelson interferometer. The experimental results show that when the frequency and amplitude of the sensed signal are set to 1 kHz and 0.4 rad, respectively, the signal-to-noise ratio with the proposed algorithm achieves a gain of 35.66 dB over the PGC-Arctan algorithm and 26.26 dB over the PGC-DCM algorithm.
本文提出了一种基于混频和除法差分的改进型相位生成载波（PGC）解调算法。从理论和实验两方面研究了相位调制深度变化和光源光强扰动对解调相位信号的影响。与传统的PGC差分校乘（PGC-DCM）和PGC反正切（PGC-Arctan）解调算法相比，改进后的解调算法通过混频提取载波调制深度，消除了解调信号的谐波失真。利用除法差分抑制了光源光强扰动引起的解调误差，提高了解调系统的稳定性。为验证该算法，基于迈克尔逊干涉仪搭建了PGC解调系统。实验结果表明，当传感信号的频率和幅度分别设置为1 kHz和0.4 rad时，所提算法的信噪比相对于PGC-Arctan算法提高了35.66 dB，相对于PGC-DCM算法提高了26.26 dB。
