用于相位缺陷检测的动态泰曼干涉仪

Dynamic Twyman Interferometer for Phase Defect Measurement

为了实现光学元件相位缺陷的大视场、高分辨率、动态检测,设计了一种动态泰曼干涉仪。该干涉仪采用短相干激光器结合迈克耳孙干涉结构产生1对相位延迟的正交偏振光,以此作为光源,通过匹配偏振型泰曼干涉仪干涉腔的相位差,补偿参考光与测试光之间的相位延迟。利用偏振相机瞬时采集4幅移相量依次相差π/2的干涉图,通过移相算法即可求解得到相位缺陷的信息。利用平面波角谱理论进行仿真,分析了二次衍射对测量结果的影响;利用琼斯矩阵法分析了偏振器件误差对测量结果的影响。实验检测了1块激光毁伤的光学平板,测试结果与Veeco NT9100白光干涉仪测量结果相比,相对误差为2.4%。此外,采用所述方法对强激光系统中光学平晶的相位疵病进行检测,测试结果显示波前峰谷值为199.2nm。结果表明,该干涉仪能够有效应用于光学元件相位缺陷的检测。

In order to realize the large field,high resolution and dynamic measurement of optical component phase defects,we design a dynamic Twyman interferometer.Based on low-coherence laser and Michelson interferometer,apair of orthogonal polarized light produced with phase delay is used as light source.By phase matching of the interference cavity,the phase delay between reference light and test light is compensated.The polarization camera is used to collect four interferograms with phase-shifting step ofπ/2,and the information of the phase defect is solved by phase-shifting algorithm.The effect of secondary diffraction on measurement results is analyzed based on the theory of the angle spectrum of plane wave.The influence of the polarizer error on the measurement results is analyzed by Jones matrix method.In the experiment,a laser-damaged optical plate is measured by this interferometer and Veeco NT9100 white light interferometer,and the relative error is 2.4%.In addition,this method is used to detect phase defects of optical flat in high power laser system,and the peak-to-valley value of wavefront is 199.2 nm.The results show that the interferometer can be used to detect phase defects of optical components,effectively.