【作者】 罗佳；

【导师】 白剑；

【作者基本信息】 浙江大学 ， 测试计量技术及仪器， 2016， 博士

【摘要】 大口径透镜广泛应用于高能激光器、惯性约束核聚变等大型光学系统中,其焦距及疵病的检测一直是光学检测领域的一个难点,已经成为制约其应用的重要因素。本文采用波前传感技术对大口径透镜的焦距进行了测量,并对透镜的疵病检测进行了一些探索和研究。提出了基于发散光及不等周期光栅的长焦距检测方法,有效实现了大口径透镜焦距值的高精度测量；提出了基于夏克-哈特曼传感器的波前检测方法,有效检测了大口径长焦距透镜中疵病所产生的涡旋相位。在焦距检测方面,本文对基于平行光及等周期光栅的焦距测量方法进行了数值分析,找出了影响测量精度的关键因素,而后提出了基于发散光及不等周期光栅的长焦距检测方法(LFMM),该方法采用发散光替代了传统的平行光,有效地避免了扫描和子口径拼接所带来的误差,实现了大口径长焦距透镜的全口径测量；同时采用不等周期光栅替代传统的等周期光栅,提高了大口径透镜的焦距检测精度。数值分析表明该方法可以从原理上提高大口径透镜的焦距检测精度。我们研制开发了完整的测量系统,该系统的焦距测量精度优于0.16%,重复性、稳定性、复现性均优于0.01%,表明该方法满足了大口径长焦距透镜焦距的全口径、高精度测量。在疵病检测方面,本文根据划痕、气沟等疵病的非连续相位特性,提出使用波前传感器对非连续相位边缘的涡旋相位进行检测,进而可实现对疵病的位置及深度的判断。本文提出了基于相位组合-相关匹配的涡旋相位位置检测法(PSC-CMM)和基于相位倾斜匹配的涡旋相位拓扑值检测法(SVMM),并对这两种方法进行了实验验证。实验结果表明,对于拓扑值-20至20的涡旋相位,其位置检测精度优于3μm,其拓扑值检测准确率达到100%,实现了对涡旋相位的位置及拓扑值的高精度检测。更多还原

【Abstract】 Ultra-long focal-length lens with large aperture (UFL) is now being widely used in large optical systems, such as high energy laser system and laser fusion system. It is a great challenge for the precise detection of its focal length and defects in the optical detection area.In this paper, we detect the UFL based on wavefront sensing techniques. A new long focal-length measurement method (LFMM) based on divergent beam and two Ronchi gratings of different periods is proposed, and features remarkably high accuracy and repeatability. Also two methods based on Shack-Hartmann wavefront sensor are proposed for the detection of phase vortex caused by the defect in the UFL.The method of long focal-length measurement is based on Talbot interferometry. In this method, a divergent laser beam is employed as an alternative to the traditional collimated beam, and the scanning system in traditional method is not needed. Meanwhile, two gratings of different periods are employed to match the divergent beam for higher measurement accuracy. From both numerical simulation and experiment, our method exhibits good performance in testing accuracy, validity, repeatability and stability.The methods of optical vortex detection are based on wavefront sensor. The defect, such as scratch and striae, causes uncontinuous phase when a wavefront passes though the lens. The phase vortex, or called optical vortex (OV), exists at the edge of the uncontinuous phase. Based on Shack-Hartmann wavefront sensor, we propose phase-slope-combining correlation matching method (PSC-CMM) for the position detection and slope vector matching method (SVMM) for the topological charge detection of OV. Both two methods work well with high accuracy in experiments. The position detecion accuracy is better than 3μm, and the accuracy rate of the topological charge detection is 100%.更多还原