基于叠层衍射成像的二元光学元件检测研究  

Detection of the binary optical element based on ptychography

作　　者：王磊[1] 窦健泰 马骏[1] 袁操今[2] 高志山[1] 魏聪[1] 张天宇[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院,南京210094 [2]南京师范大学物理科学与技术学院,南京210097

出　　处：《物理学报》2017年第9期139-147,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61377015;61505080;61575095);中国科协"青年人才托举工程"(批准号:2015QNRC001);中央高校基本科研业务费专项资金(批准号:30920130111007)资助的课题~~

摘　　要：本文提出了一种基于叠层衍射成像(ptychography)的二元光学元件的检测方法,该方法可实现对二元光学元件表面微观轮廓的检测以及特征尺寸的标定.相比于传统的二元光学元件检测方法,其使用无透镜成像技术,简化了系统结构并可适用于特殊环境下的检测.该方法可直接通过采集多幅衍射图,利用叠层衍射成像迭代算法可精确地复原大尺寸待测元件的表面微观轮廓,提高大尺寸器件的检测效率.本文模拟仿真了台阶高度与噪声大小对纯相位台阶板复原结果的影响,并在光学实验中选取计算全息板为样品,复原样品的表面微观轮廓信息以及得到台阶高度.以白光干涉仪检测结果为标准,该方法在精度要求不太高的前提下,可获得令人满意的成像质量.Due to the extremely high diffractive efficiency and flexible design freedom, binary optical element can realize specific function in the optical system in comparison with the traditional refractive optical element. Ptychography, which is a typical lensless optical imaging technology with simple structure, has the advantages of the extensible imaging range and high resolution. The topography of binary optical element can produce the phase difference between the illumination and transmission fields. The features of binary optical element are based on the complex amplitude modulation. So we can obtain the complex transmission function by using ptychography to realize the phase retrieval. In this paper, we propose a detection method for binary diffractive optical element based on ptychography. An improved ptychography optical system is designed by using the combination of variable aperture and lens to control the illumination field. Because the illumination field is a diverging spherical wave, the diffractive patterns can avoid the high contrast and the reconstruction result will contain more details of the sample. The proposed method can not only inspect a large region of the binary optical element, but also calibrate its feature size, such as step height. Compared with the traditional binary optical element detection methods, the proposed method can simplify the system structure, and it can be applied to special environment by using lensless imaging technology. The increasing of the diffraction pattern numbers can acquire the topography of the large size sample and improve the detection efficiency. Taking a phase step plate for sample, the simulations are conducted to analyze the influences of step height and noise on the recovery result. The results show that the detection range of step height is less than 1.5A. We can realize a preferable sample reconstruction when the noise of diffraction pattern is less than 5%. A computer-generated holography （CGH） is reconstructed by using the extended ptychographic iter

关 键 词：叠层衍射成像 二元光学元件 相位复原 特征尺寸标定 

分 类 号：O436.1[机械工程—光学工程]