为了消除环境因素(尤其是振动和温度波动)在物体表面三维形貌测量中的影响,基于正弦相位调制(SPM)发展了一种光纤干涉条纹相位稳定技术。利用马赫-泽德光纤干涉仪结构和杨氏双孔干涉原理实现高密度的余弦分布干涉条纹投射。利用两光纤干涉臂端面的菲涅尔反射生成迈克尔逊干涉信号,由光电探测器(PD)检测后送入相位控制系统。采用相位生成载波的方法提取干涉信号的相位,并将生成的补偿信号闭环反馈给压电陶瓷驱动器,与正弦相位调制信号相加后共同驱动压电陶瓷,补偿环境因素带来的相位漂移,实现干涉条纹相位的稳定。环境因素对条纹相位的影响低于57 mrad,实验结果验证了该方法可行性。

Aimed at eliminating the effect of the environmental factors (especially the vibration and temperature fluctuation) for 3D profilometry measurement, a method based on the Sinusoidal Phase Modulation (SPM) is developed to stabilize the phase of fiber interference fringes. The system makes use of the Mach-Zehnder interferometer structure and Young’s double pinhole interference principle to achieve the high-density interference fringe projection of cosine distribution. The Fresnel reflection on the exit faces of two interference arms is used to generate a Michelson interference signal, which is detected by the Photoelectric Detector (PD) and send into Phase Control System (PCS). We extract the phase of the Michelson interference signal, then feedback the compensation signal to the Piezoelectric Transducer (PZT)driver, and drive the PZT with sinusoidal phase modulating signal together. The phase shift brought by the environmental factors can be compensated, and a well stability of the fringe phase can be achieved. The phase shift can be reduced to 57mrad, and experiment has verified the feasibility of the proposed method.