【作者】 陈小梅；

【导师】 周素梅；

【作者基本信息】 西南大学 ， 光学， 2012， 硕士

【摘要】 光学器件的微型化、阵列化,集成化成为当代光学发展的重要方向,微透镜阵列的成功研制,无疑对光学器件的微型化和阵列化起了重要作用,它使微光学器件在光通信、光存储、光学互联、光开关、光信息加工和微光学传感器等方面具有广泛的应用。2008年国内采用光刻离子交换法首次成功研制了方形孔径平面微透镜阵列,这一成果极大的提高了透镜阵列的填充系数,使填充率在理论上达到100%,实验上也取得了非常大的提高。但是该阵列存在两个重大问题：一方面,采用光刻离子交换工艺制作方形孔径平面微透镜阵列,制作出的样品的焦距和数值孔径不易控制,即焦距和数值孔径的大小与离子交换时间之间没有定量的关系,这使制作对应参数的方形孔径平面微透镜阵列难度加大。另一方面,由于平面微透镜阵列系统常被用作轴上点成像,其球差大大影响了成像品质,不容忽视。为了解决焦距和数值孔径不易控制的难题,本文在离子交换理论的基础上,选取合适的模板参数、设定不同的离子交换时间,进行了大量的分时段实验,并将实验结果与理论值对比,实验结果可为制作一定范围内的焦距和数值孔径的方形孔径微透镜阵列提供一定参考依据。针对球差大大影响成像效果的问题,首先采用平行光入射法和光瞳出射法测量了方形孔径平面微透镜阵列的纵向球差,并结合几何光学和数学方法计算出横向球差。同时本文从制作方形孔径的玻璃材料的内部结构特征出发,采用退火处理改善透镜阵列内部的折射率分布,使折射率分布接近理想分布,从而改善透镜阵列的球差。本文还依据平面微透镜阵列焦斑连续可调原理,在理论上提出了方形孔径平面微透镜阵列系统的焦距连续可调的方案。具有高填充率、合适的数值孔径和焦距,且焦距连续可调的平面微透镜阵列将在均匀辐照系统、高质量成像系统及长焦距测量系统等方面取得广泛的应用。本文未涉及综合成像和其他一些重要的测量将在后期的工作中进一步研究。更多还原

【Abstract】 Microlens array has become a hot topic in microoptics recently, and noncircular aperture microlens array has been proposed as a new subject. Photo etching technology, ion-exchanging technology and especial removing Ti film process were applied to fabricate square-aperture planar microlens array (PMLA). The filling factor of array was approximate100%and its imaging resolution ratio was improved greatly. With those high performances, square-aperture PMLA plays an important role in optical fields, such as optical information processing, optical interconnects, information storage, optical communication, optical switch and imaging of laser sensors and so on.However, numerical aperture (N.A.) and focal length (F) of square-aperture PMLA were difficult to design and the aberration, especially spherical aberration, can not be ignored. To solve these two problems, experiments and theory analysis have been done in this paper.Firstly, thermal diffusion theory of ion was used to analyze the influence on N.A and F of PMLA with ion-exchanging time; meanwhile, N.A and F were investigated with different ion-exchanging time but the same size of mask aperture experimentally. Experimental results are comparable with theory analysis. These results can be used as a reference for designing square-aperture PMLA with appropriate N.A and F by setting optimal ion-exchanging time and also as a reference to obtain the best ion-exchanging time as the same time to obtain the big N.A and F.Secondly, we dealt with square-aperture PMLA by annealing treatmen, and the longitudinal and transverse spherical aberration by the method of parallel light incidence and emergent light pupil. These experimental results showed that the refractive index distribution was closer to ideal distribution and the spherical aberration was decreased obviously after annealing technology. Meanwhile, imaging resolution ratios are also improved more greatly.Thirdly, the optical system with controllable focus spot was proposed with two pieces of the square-aperture PMLA which has continuously adjustable F and an aspherical lens. F can be adjusted continuously just by precisely adjusting the distance between the two pieces of square aperture PMLA. According to the high filling factor, fitting N.A and F, continuously adjustable F and small spherical aberration, this square-aperture PMLA has a prospect application in more optical systems, such as, uniform irradiation systems, higher quality imaging systems, long focal length measuring systems and so on. The study of comprehensive imaging and some important measuring will be done in the future.更多还原