【作者】 吴新民；

【导师】 陈进榜；

【作者基本信息】 南京理工大学 ， 光学工程， 2002， 博士

【摘要】 移相干涉术(PSI)作为快速、非接触的精密测量手段，已经广泛地应用于光学零件、光学系统、精密表面检测和其它一些与光程差参数相关的物理量的测量(如温度场、密度场等)。它的基本测量原理是，通过摄像系统(CCD)接受到的干涉图中空间坐标已知的各个像素点的光强信号，在压电晶体驱动参考光程有序变化时，采集到多幅干涉图的光强信号，由移相干涉法，由光强值得到被测光程差值(位相值)。通过严格控制环境条件(温度、气流、振动等)，其理论光程差(位相)的最小分辨率可以达到nm的数量级。然而，由于干涉计量测试灵敏度高、精度高，对外界振动非常敏感，使它的应用范围受到限制。为了进一步拓展干涉仪的用途，发展移相干涉技术，本文结合导师的研究项目，在光干涉抗振技术方面做一些前瞻性、探索性的研究。 本文分析了干涉测量技术中存在的主要误差来源，通过对通常环境下振源特性的分析，得到了对干涉测试影响较大的振源的频率范围主要在30Hz以下，确定了抗振补偿的目标和技术指标是使干涉仪的振动频率＜50Hz，振幅～1μm。创新性地提出了一种新的自适应抗振技术——条纹细分测振技术，可以探测到很小(本文中为1／400个条纹间距)的条纹移动量。建立了位相调制条纹细分技术的数学物理模型，提出了用硬件实现条纹移动探测技术途径。建立了一套闭环的自适应抗振干涉测试硬件系统，成功实现了实时地探测干涉条纹移动量和移动方向。提出了填充脉冲数预设定的方法，可以将干涉条纹锁定在任意设定的位相位置，实现了用PZT同时实现振动补偿和移相测量；深入分析讨论了PZT的延迟问题，创造性地提出了用多次逼近补偿的办法，给出了反馈补偿的算法，解决了补偿过程中存在的系统不稳定和过补偿的问题。详细分析了影响抗振效果的主要因素，定量地给出了其对结果的影响的大小。在实验系统中，设计并实现了带耦合系统的单模光纤导光系统，使光源和干涉仪主体的可以分离。实验验证和测试结果表明，本自适应系统可以较好地补偿50Hz以下的大振幅(条纹移动一个条纹间隔左右)振动。即使在振动较大的环境里，也可以实现干涉测量。更多还原

【Abstract】 Phase shifting interferometry (PSI) has been widely used and accepted as a fast and accurate non-contact metrology tool. It is widely used to measure optical element, optical system, detection of optical surface and the physical quantities(such as field of temperature, field of density) related with optical path difference .The underlying measurement principle of PSI is to determine the phase of the intensity signal in interferogram received at each pixel of an imaging device. With the regular move of PZT, it can obtain intensity signal of several interferograms. Then the optical path difference can be obtained with PSI algorithm and to use the phase value for each pixel to determine a height value for each pixel. A primary advantage of PSI is its high precision. With careful control of environmental conditions, measurement precision to the nanometer scale or below is possible with PSI. However, one of the most serious impediments to wider use and improve precision of PSI is its sensitivity to external vibration with the consequence that PSI has rarely been used in a manufacturing in-situ and some special situations, such as that the optical path is very long or the detected unit is very large. Instead, PSI has been relegated to use during post-manufacturing inspection. Combined with the research project of my tutor and to extend the use of interferometer and to develop the interferometry, in this paper, some studies on vibration-resistant for interferometry have been prior considered in creationary and exploring way.In this thesis, the general error sources for PSI are analyzed. We find that the relatively low-frequency vibrations at 50Hz and lower are the main problem through the analysis of the vibration sources in usual environment. A new vibration compensation method, phase modulating interference fringes fractionizing technology, has been put forward in a creative way. It simulates the fringe’s move by the phase difference of signals. It can detect the fringe’s move by 1/400 of the space of two neighboring fringes with fractionizing technology. A new mathematical and physical models based on the method are established. And the ways to carry out the models by full electric circuit are proposed. We build a close vibration compensation system which can successfully achieve the measurement of interference fringesmovement and -vibration compensation. It puts forward pre-setting fill-in pulses method to implement phase shifting with the same PZT. With this new method, the interference fringe can be stabilized at any pre-setting phase position. A new feedback algorithm is brought forward to overcome the instability of the system. It uses 3 times approaching vibration compensation method. A pigtail with laser coupling lenses as a point light source of interferometer is designed. It can be separately used to the body of interferometer. Experiments were carried out on a smooth mirror surface excited that the technique was found to be immune to vibration of serious vibrations at 50Hz or lower. Finally, the main resources of errors to influence the effects of vibration compensation and PSI measurement results are discussed in detail.更多还原