基于差分的激光自混合光栅干涉位移测量  

Displacement Measurement of Self-Mixing Grating Interferometer Based on Difference

作　　者：曹雪[1] 冯立娜 王秀芳[1] 张忠伟[1] CAO Xue;FENG Lina;WANG Xiufang;ZHANG Zhongwei(School of Electrical and Information Engineering,Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]东北石油大学电气信息工程学院,黑龙江大庆163318

出　　处：《吉林大学学报（信息科学版）》2023年第4期583-589,共7页Journal of Jilin University（Information Science Edition）

基　　金：黑龙江省自然科学基金资助项目(LH2022E024)。

摘　　要：为使信号在不失真的情况下降低共模噪声的干扰,提高激光自混合光栅干涉信号的信噪比,提出了一种基于差分技术的激光自混合光栅干涉位移测量方法。+1级衍射光被振动物体反射后返回激光腔,发生自混合干涉,并由封装在激光器内的光电探测器PD1接收,0级衍射光由外置PD_(2)接收。根据半导体激光器前后向输出存在180°相位差的原理,两光束所携带的自混合干涉信号相位相反,而叠加的噪声是部分相关的,因此对两个干涉信号进行差分能消除部分噪声。通过对差分后的自混合信号处理,可以重构出位移。实验结果表明,差分后的重构振动波形的平均误差更小,信号更平稳,且差分后的干涉信号的信噪比提高3 dB以上。In order to reduce the interference of common mode noise and improve the SNR(Signal-to-Noise Ratio)of laser self-mixing grating interference signal under the condition of signal loss,a method of measuring the interference displacement of laser self-mixing grating based on differential technology is proposed.The+1 diffraction light is reflected by the vibrating object and returns to the laser cavity,where self-mixing interference occurs and is received by the photodetector PD1 encapsulated in the laser,while the 0 diffraction light is received by the external photodetector PD_(2).According to the principle that there is phase difference in the forward and backward output of semiconductor laser,the phase of the self-mixing interference signal carried by the two beams is opposite,and the superimposed noise is partially correlated,so the difference between the two interference signals can eliminate part of the noise.By processing the differential self-mixing signal,the displacement can be reconstructed.The experimental results show that the mean error of the reconstructed vibration waveform is smaller,the signal is more stable,and the signal-to-noise ratio of the interference signal is improved by no less than 3 dB.

关 键 词：自混合干涉 衍射光栅 位移传感 半导体激光器 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TH741[自动化与计算机技术—控制科学与工程]