移相干涉仪的主动抗振技术:光强-相位法振动探测与补偿

光学干涉测量易受环境振动的影响 ,本文提出了一种机电反馈式主动抗振方案 :光强 -相位法振动探测与补偿技术。在这个方案中 ,光电探测器测量干涉场中任意一点的光强因振动产生波动的情况 ,据此得到波前相位的变化量 ,经PZT光学移相器对波前相位采取象限区分反馈法进行实时校正。实验结果表明 ,这种方案可以对频率小于 5 0Hz、幅度小于 1/2光波波长的低频环境振动进行有效补偿 ,得到了稳定的条纹干涉图 ,同时还能进行移相测量

Active phase - shifting interferometry:wave - front phase directly derived from light intensity for vibration determination and compensation

Interferometry is sensitive to environment vibration.In this paper,a simple and robust vibration-resistant method for phase-shifting interferometer is presented.In this method,light intensity of an arbitrary point in interferometric field,which is usually fluctuant own to environment vibration,is measured by a photoelectric detector.Then,the change of wave-front phase is directly derived from fluctuant light intensity.Based on phase change,a piezoelectric transducer(PZT)is used for compensating the variation of wave-front by quadrant-identified feedback technique.Therefore,the steady interferometric field is gained.The experimental results show this method could efficiently compensate the low-frequency environment vibration (frequency less than 50Hz,amplitude about at 1/2 wave)to interferometer,stable interferograms are obtained,and phase shift testing could be successfully carried out in the presence of external perturbations.