基于条纹投射和正弦相位调制技术，提出了一种用于测量物体表面三维形貌信息的光纤干涉系统。通过杨氏双孔结构实现了条纹投射，并以余弦电压信号驱动压电陶瓷实现正弦相位调制。为了消除机械振动、温度波动等外部干扰，采用相位控制系统对相位漂移进行检测，并生成实时相位补偿信号。补偿后相位误差可达6.8 mrad，从而获得高精度的干涉条纹相位稳定度。对待测件的表面轮廓连续测量两次，时间间隔为10 min，测量重复度达到0.05波长。实验结果证明：该系统能够实现较高精度的表面形貌测量。

A fiber-optic interferometer based on fringe projection and sinusoidal phase modulation(SPM)for three-dimensional surface profile measurement was presented. It made use of Young’s double pinhole interference principle to achieve fringe projection. And sinusoidal phase modulation was accomplished by driving piezoelectric transducer using a cosine voltage single. To eliminate the external disturbances such as mechanical vibration and temperature fluctuation, a phase control system was proposed by detecting the phase drift and giving real-time compensation. The phase error was reduced to 6.8 mrad after compensating. A high phase stability of the interference fringe can be achieved. By measuring the surface profile of a glass plate for two times over an interval of 10 min, the repeatability is about 0.05 wave. Experimental results show that the proposed interferometer can be used for surface profile measurement with a high precision.