基于二元光学元件的三维聚焦光场整形技术
文献类型：学位论文
| 作者 | 余俊杰 |
| 学位类别 | 博士 |
| 答辩日期 | 2012 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 周常河 |
| 关键词 | 二元相位光瞳滤波器，达曼相位编码，聚焦双Bessel光束，聚焦焦斑阵列，三维涡旋阵列 |
| 其他题名 | Three-dimensional focus reshaping using binary optical elements |
| 中文摘要 | 透镜是一种重要的基础光学元件。透镜的原始聚焦光场（对成像称点扩散函数）由于衍射效应其横向光斑和轴向焦深总是存在分辨率极限。另外，对单束激光普通透镜一般只能产生单个聚焦光斑。然而，在某些实际应用场合，人们对聚焦光场有一些特殊要求，例如同时拥有高横向分辨率、超长焦深和大轴向偏振分量的聚焦光场在激光粒子加速中有非常重要的应用。于是，人们利用各种方案对原始的透镜聚焦光场进行三维整形，从而实现包括横向和轴向超分辨、延长焦深的“光针”、环形聚焦光斑、聚焦光斑阵列等一系列的新型光场分布。在所有方案中，相位型二元光瞳滤波器以其高性能、实施简便、低成本受到人们普遍关注。如今，这些利用各种光瞳滤波器实现的新型聚焦光场被广泛应用于各种显微成像技术、光学操控、粒子加速、先进光刻、光存储和激光加工等领域。本论文基于本课题组在微光学尤其是二元光学方面的技术积累，设计了一系列新型相位型二元衍射光学元件以实现聚焦光场的各种三维整形效果，并探讨了各种整形聚焦光场在相应方面的应用。本论文的主要内容如下： 1.二元相位光瞳滤波器（BPF）实现超分辨、延长焦深和轴向焦移方面的研究。首先，在本课题组光瞳超分辨技术的研究基础上，我们给出了BPF的通用设计方法，并以实际的超分辨光存储系统为例，通过约束条件下的优化算法设计了能够同时实现横向超分辨和轴向延长焦深的BPF结构，该工作发表在[Opt. Commun. 283, 4171-4177, (2010)]。其次，我们详细研究了德拜标量衍射理论下的非相位BPF的轴向焦移和色散特性，提出了利用这种非相位BPF的色散特性对单透镜飞秒聚焦光场的色散补偿方案，该工作发表在[SPIE Proc. 7848, 784815 (2010)]。第三，我们在本课题前人工作基础上，从实验上验证了基于BPF红光高清方案，顺利读取物理密度15G单面双层光盘。最后，我们提出了利用延长焦深的BPF结合一维达曼光栅实现的延长焦深的多路激光直写方案。 2.高数值孔径下的圆环达曼光栅以及利用圆环达曼光栅产生聚焦无衍射双Bessel光束方面的研究。在德拜矢量衍射理论基础上，我们从理论和实验上实现了高数值孔径下的单周期圆环达曼光栅。结果表明，这种高数值孔径下的圆环达曼光栅的聚焦环形光斑的尺寸在微米量级，而中心的暗斑可以达到亚微米量级，该工作发表在[Appl. Opt. 51, 994-999 (2012)]。另外，我们提出了利用一阶圆环达曼光栅实现的聚焦无衍射双Bessel光束，聚焦光场的横向光斑尺寸在亚波长量级，而轴向焦深可达10～102波长量级。这种聚焦双Bessel光束在激光加工、粒子加速等方面有重要应用价值，该工作已投稿于Optics Communications。 3.达曼波带片、扭曲达曼光栅以及三维达曼阵列方面的研究。首先，基于德拜矢量衍射理论，我们将达曼相位编码的思想引入传统波带片结构中，提出了一种新型衍射光学器件——达曼波带片。这种新型的衍射光学器件能够在透镜的后场产生多个等强度的轴向聚焦光斑，从而使普通的透镜变成一个轴向多焦点系统。其次，我们利用这种达曼波带片和二维达曼光栅相结合，在透镜的聚焦后场实现了聚焦光斑的三维晶格排布结构，我们称之为三维达曼阵列。这种聚焦光斑的三维达曼阵列可以应用于三维并行光学操控、三维激光直写等场合，该工作已发表在[Appl. Opt. 51, 1619-1630 (2012)]。另外，类比扭曲光栅，我们提出了扭曲达曼光栅。这种扭曲达曼光栅结合透镜形成的聚焦系统用于聚焦则可以产生沿轴向和横向同时移位的多焦点阵列，这种特性意味着当该聚焦系统用于成像的时候，可以实现多个轴向物面同时成像于同一个像平面上。因而，这种扭曲达曼光栅可以用于实时三维成像和三维粒子跟踪。相比于传统的扭曲光栅，这种扭曲达曼光栅能够将同时成像的物面个数拓展到10～103量级，因而使得同时实现高轴向分辨率和大轴向成像范围的实时三维成像成为可能，该工作有待整理发表。 4.螺旋达曼波带片和达曼涡旋阵列方面的研究。基于三维达曼阵列的工作，我们通过引入涡旋入射光场在聚焦透镜的后场实现了三维单极涡旋阵列，即由一系列具有相同拓扑荷的涡旋排布成三维晶格结构。其中，这种涡旋入射光场是通过达曼涡旋光栅产生的。我们利用一个反射镜的平移和转动来选择达曼涡旋光栅的不同衍射级次作为入射光场，从而使得三维单极涡旋阵列的拓扑荷在一定范围内可调，该工作已发表在[Appl. Opt. 51, 2485-2490 (2012)]。其次，我们将涡旋相位结构通过达曼编码的方式引入到达曼波带片中，提出了螺旋达曼波带片。这种螺旋达曼波带片可以在聚焦透镜后场产生多个共轴的偶极涡旋。这种偶极涡旋阵列中的每个涡旋所携带的拓扑荷不同，而总的拓扑荷保持为零。最后，结合这种螺旋达曼波带片和二维达曼光栅，我们实现了三维的偶极涡旋阵列。通过引入不同涡旋入射光场，我们能够对特定的某个轴向焦面内的二维涡旋阵列的拓扑荷进行调节，从而有望实现利用这种三维偶极涡旋阵列捕获的粒子在不同轴向平面内传输。 |
| 英文摘要 | A lens is one of the most basic and important optical elements. The original focused field of a lens (or called the point spread function when it is used for imaging) always possesses limited resolving power and limited depth of focus (DOF) because of diffraction. In addition, a conventional lens only produces a single focus spot for one shot of laser. However, in some practical applications, some special focused fields are desired, e.g., the focused field with high transverse resolution, ultralong DOF and large longitudinal polarization component is attractive for particle laser acceleration. Therefore, various schemes are proposed for three-dimensional (3D) focus reshaping, including transverse and axial superresolution, generation of “optical needle” with ultralong DOF, annular focused field and focus spot arrays. Among all of these schemes, the pupil filter is outstanding due to its high performance, ease of implementation and also low-cost. Nowadays, the 3D focus reshaping using various pupil filters has found applications in many areas, such as optical microscope, optical manipulation, photolithography, optical data storage and laser machining, etc. Here, based on the research accumulation on micro-optics, especially binary optics, in our group, we design several novel diffractive optical elements (DOEs) for 3D focus reshaping and also discuss its potential application for each new DOE. The main contents of this dissertation are as follows: 1.Research on realization of superresolution, extension of DOF and axial focal shift using binary pure-phase filters (BPFs). First, on the basis of the research accumulation of superresolution pupil filters in our group, we give the general method of designing BPFs for various applications. As an example, we design two kinds of BPFs for improving the storage capability of a practical red-light high-density optical pickup system, which can simultaneously achieve transverse superresolution and extension of DOF, and this work has been published on Opt. Commun. 283, 4171-4177, (2010). Second, the focal shift effect and axial dispersion property of BPFs with non- phase shift in focusing systems are described in the regime of the scalar Debye theory, and the scheme of the application of BPFs with negative axial dispersion in compensation of chromatic aberration of a single lens in an ultrashort laser focusing system is presented. This work has been published on SPIE Proc. 7848, 784815 (2010). Third, based on the former research results in our group, we experimentally verify the scheme of the red-light high-density optical data storage employing BPFs, and the results show that the pickup with a specially designed BPF can successfully read out 15 Gbyte disks. Finally, we propose the scheme of parallel direct laser writing with extended DOF by combination of a BPF with extended DOF and a 1D Dammann grating. 2.Research on circular Dammann grating (CDG) under high numerical-aperture (NA) focusing and generation of focused twin Bessel beams using CDG. The CDG with single period under high-NA focusing is theoretically and experimentally demonstrated in the regime of Debye vectorial diffraction theory. The results show that the size of the whole annular pattern is in micrometer scale and the dark center is submicron-sized. This work has been published on Appl. Opt. 51, 994-999 (2012). In addition, generation of focused twin Bessel beams using one-order CDG is described. The results show that the transverse size of the central lobe is in subwavelength scale and the depth of focus can reach as long as 10~102. This kind of focused twin Bessel beams with ultralong DOF can be used in laser machining and particle acceleration, and this work has been submitted to Optics Communications. 3.Research on Dammann zone plate (DZP), distorted Dammann grating (DDG) and 3D Dammann array. First, based on Debye vectorial diffraction theory, we introduce the Dammann phase encoding method into the structure of conventional zone plates and propose a new DOE, called a Dammann zone plate. This new DZP can produce a series of coaxial focus spots with good uniformity and high efficiency in the focal region. Second, by combining a DZP and another 2D Dammann grating, we demonstrate a scheme that can produce a 3D focus spot array in a 3D lattice structure, called a 3D Dammann array, in focal region of an objective. This 3D Dammann array can be used for 3D parallel optical manipulation and 3D direct laser writing, and this work has been published on Appl. Opt. 51, 1619-1630 (2012). In addition, analogizing the conventional distorted grating, we propose the concept of distorted Dammann grating, which can produce tens of focus spots shifting along both the transverse and axial directions when it is located before a focusing lens. This property implies that the combination of a DDG and a focusing lens can be used for simultaneous imaging multiple object layers onto a single image plane, and this DDG can be used for real-time 3D imaging and 3D particle tracking. Compared with the conventional distorted grating, this DDG increases the number of object layers for simultaneous imaging to 10~103, and thus it enables one to simultaneously achieve real-time 3D imaging with high axial resolution and large axial imaging range. This work is under preparation for submission. 4.Research on spiral Dammann zone plate (SDZP) and Dammann vortex array. First, we introduce a vortex beam as the incident field into the focusing system of the aforementioned 3D Dammann array and realize a kind of true 3D array of focused monopole vortices with tunable topological charge. The vortex beam is produced by a Dammann vortex grating (DVG), and a scheme based on this DVG and a mirror is proposed to provide a choice for changing the topological charge of the 3D monopole vortex array. This work has been published on Appl. Opt. 51, 2485-2490 (2012). Second, by nesting a spiral phase structure into the DZP, we propose another DOE called a spiral Dammann zone plate. This SDZP can generate a series of dipole vortex array along the optical axis in the focal region. This dipole vortex array possesses opposite charges for the ±mth orders and thus the total charge is always zero. Finally, combining a SDZP and another 2D Dammann grating, we demonstrate a kind of 3D dipole vortex arrays in the focal volume of an objective. The topological charges of those 2D dipole vortex arrays on several coaxial planes could be tuned by changing the charge of the incident vortex beam, which implies that the focused vortex array on one certain cross-sectional plane can be freely manipulated and the trapped particles could be transported among different coaxial planes when this 3D dipole vortex array is used for optical trapping. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15721]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 余俊杰. 基于二元光学元件的三维聚焦光场整形技术[D]. 中国科学院上海光学精密机械研究所. 2012. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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