基于微透镜阵列匀束的激光二极管面阵抽运耦合系统分析

为了提升高功率固体激光器中激光二极管(LD)面阵抽运场性能,采用几何光学和数理统计分析的方法,建立了基于微透镜阵列匀束的LD面阵抽运耦合系统的数学与物理模型,对微透镜阵列参数与最终耦合输出抽运场参数之间的关系进行分析,明确了微透镜单元F数、微透镜通光单元数以及微透镜阵列空间周期参数的设计原则.经实验测试,优化设计完成的LD面阵抽运耦合系统光场不均匀度为7.9%,耦合效率为90.7%.     

紫外衍射微透镜阵列的设计与制备

为了提高紫外焦平面阵列的填充因子,可以通过微透镜阵列与紫外焦平面阵列的集成,以改善紫外焦平面阵列的探测性能。根据标量衍射理论设计了用于日盲型紫外焦平面阵列的128×128衍射微透镜阵列,其工作中心波长为350nm,单元透镜F数为F/3.56。采用组合多层镀膜与剥离的工艺方法制备了128×128衍射微透镜阵列,对具体的工艺流程和制备误差进行了分析,测量了衍射微透镜阵列的光学性能。实验结果表明:衍射微透镜阵列的衍射效率为88%,与理论值95%有偏差,制备误差主要来自对准误差和线宽误差。紫外衍射微透镜阵列具有均匀的焦斑分布,与紫外焦平面阵列单片集成能较好地改善器件的整体性能。     

Monolithic integration technique for microlens arrays with infrared focal plane arrays

Based on scalar diffraction theory, 8-phase-level 256×290 element diffractive microlens arrays with lenslet dimension of 50×33 μm² have been fabricated on the back side of PtSi infrared focal plane arrays. The design and fabrication process are discussed. The measurement results indicate that the imaging quality has been greatly improved and the ratio of the signal-to-noise of the infrared focal plane array integration with microlens array is increased by a factor of 2.5.     

飞秒激光和酸刻蚀方法制作凹面微透镜阵列

基于飞秒激光光刻技术和氢氟酸对光学玻璃的刻蚀,在K9光学玻璃表面制作了凹面微透镜阵列,并且可以以此为模板实现凸微透镜阵列的大量复制.用相位对比显微镜和扫描电子显微镜分析了微透镜阵列的表面轮廓,测试了微透镜阵列的光学衍射特征.该方法简单、透镜参量可控,制作的微透镜阵列能够用于分光、光束匀化、并行光刻等强激光领域.     

凹折射微透镜阵列的离子束刻蚀制作

利用光刻热熔成形工艺及离子束刻蚀制作 12 8× 12 8元凹微透镜阵列。所制硅及石英凹微透镜的典型基本图形分别为凹球冠形、凹柱形和矩顶凹面形。分析了在光致抗蚀剂柱凹微透镜图形制作过程中的膜系匹配特性 ,与制作该种微透镜有关的光掩模版的主要结构参数 ,以及光致抗蚀剂掩模工艺参数的控制依据等。探讨了在凹微透镜器件制作基础上利用成膜工艺开展平面折射微透镜器件制作的问题。采用扫描电子显微镜 (SEM)和表面轮廓仪测试了所制石英凹微透镜阵列的表面微结构形貌。给出了所制石英凹微透镜阵列远场光学特性的测试结果。     

微透镜阵列误差对半导体激光匀化性能的影响

为了减小微透镜阵列误差对匀化光斑的影响,深入研究微透镜阵列光束匀化系统中微透镜阵列相对位置误差对光束匀化性能的影响,设计了一种微透镜阵列光束匀化系统。依据相对位置误差类型的不同,将双列微透镜阵列间六个自由度变化导致的误差分为距离误差、偏移误差以及转动误差进行分析,并对每种误差对光束匀化性能的影响进行了研究。采用6板条半导体激光器堆栈对上述匀化系统进行实验验证,实现了均匀性为90.75%的光斑,并对系统影响光斑性能的原因进行了分析。     

Fabrication of PDMS microlens array by digital maskless grayscale lithography and replica molding technique

This paper presents a facile and effective method to fabricate microlens array in polydimethylsiloxane (PDMS). The microlens array model is fabricated in photoresist via digital maskless grayscale lithography technique and the replica molding technique is used to fabricate PDMS microlens array. A convex PDMS microlens array with rectangular aperture and concave PDMS microlens array with hexagonal aperture are fabricated. The morphological characteristics of the microlens arrays are measured by microscope and 3D profiler. The results indicate that the profiles of the PDMS microlens arrays are clear and distinct. This method provides a simple and low-cost approach to prepare large area, concave or convex with arbitrary shape microlens array, which has potential application in many optoelectronic devices.     

微透镜阵列光学相控阵扫描技术研究进展

光学相控阵光束扫描技术在激光雷达、空间光通信和光开关等领域拥有巨大的应用潜力。微透镜阵列光学相控阵可以通过微透镜阵列间μm量级的相对位移同时对多个出射光束的二维倾斜相位进行调制,从而实现大角度二维光束扫描,具有出射口径大、结构简单、体积小、微惯性、多功能等优点。首先介绍了微透镜阵列光学相控阵的扫描原理,之后对微透镜阵列光学相控阵国内外的发展现状、应用和现阶段存在的问题进行了阐述,最后对微透镜阵列光学相控阵的发展趋势进行了展望。     

微透镜变化对半导体激光器光束匀化效果的影响

为了实现高均匀性的半导体激光器泵浦光源,研究了成像型光束积分器中微透镜的变化对泵浦光均匀性的影响。详细讨论了微透镜数值孔径与入射光束的角度匹配的问题。推导了高斯光束经成像型光束积分器的光场分布模型,分析了微透镜的边缘衍射对光斑均匀性的影响,明确了微透镜孔径大小的取值范围,并利用ZEMAX进行了系统仿真及实验验证。结果表明,经优化后的成像型光束积分器实现了不均匀性为8.11%的矩形光斑。     

Model analysis of effect of diffraction focus characteristics of microlens arrays on parallel laser direct writing quality

In order to study the effect of diffraction focusing characteristics of microlens arrays on the parallel laser direct writing quality, we use nonparaxial approximation to analyze the diffraction focus characteristic of a single microlens, take into consideration the cross-talk effect of a number of microlenses on the diffraction focusing characteristics of an array, and establish a theoretical focusing intensity model of a microlens array to describe the influence of a change in F-number and/or center distance on the diffraction focusing characteristics of a parallel laser direct writing system while incident writing laser is normal. Numerical simulation results indicate that there is a cross-talk effect among microlenses which increases as the F-number increases when the center distance is the same as the smaller aperture, and parallel writing quality can be improved by reducing or totally eliminating the cross-talk effect by reducing F-number and/or increasing center distance.     

Research on micro-optical lenses fabrication technology

We present a detail investigation on the development of a series of gradient index (GRIN) optical glass microlens and polymer microlens and microlens arrays in our laboratory in recent years. The special glass material GRIN lenses have been fabricated mainly by using ion-exchange technology, which are applied to construct micro-optic devices and other applications. On one hand, we demonstrated the light propagation and imaging properties of GRIN lenses and the results analyzed. On the other hand, we have explored a drop-on-demand ink-jet printing method to produce microlens array using nano-scale polymer droplets involved with a uniform ultraviolet light and heat solidifying process. The experimental setup for manufacturing polymer microlens array and the performance of refractive microlens elements are also given in this paper.     

Array illuminator based on self-imaging in white light

An array illuminator is a device/optical system that splits an incoming beam of light into an array of many light spots/beams. It is useful in logic systems and in optical digital computing or in switching systems to energize arrays of components such as logic gates, optically bistable devices and electro-optic modulators. Array illuminators working in white light are interesting because they do not suffer from coherent noise and yield better signal-to-noise ratio. We propose configurations for array illuminator based on Fresnel diffraction and working under white light illumination conditions. Performance evaluation of the illuminators is also undertaken and the results of investigation are reported.     

Fabrication of Refractive Microlens Array with no Dead Area

ＦａｂｒｉｃａｔｉｏｎｏｆＲｅｆｒａｃｔｉｖｅＭｉｃｒｏｌｅｎｓＡｒａｙｗｉｔｈｎｏＤｅａｄＡｒｅａＣＨＥＮＢｏＧＵＯＬｕｒｏｎｇＴＡＮＧＪｉｙｕｅＺＨＥＮＨｏｎｇｊｕｎＰＡＮＧＬｉｎｇＴＩＡＮＷｅｉｊｉａｎ（ＩｎｆｏｒｍａｔｉｏｎＯｐｔｉｃｓＲｅ...     

Multiphoton multifocal microscopy exploiting a diffractive optical element

Multiphoton multifocal microscopy (MMM) usually has been achieved through a combination of galvo scanners with microlens arrays, with rotating disks of microlens arrays, and cascaded beam splitters with asynchronous rastering of scanning mirrors. Here we describe the achievement of a neat and compact MMM by use of a high-diffraction-efficiency diffractive-optic element that generates a multiple-spot grid of uniform intensity to achieve higher fidelity in imaging of live cells at adequate speeds.     

小F数衍射微透镜阵列光学性能研究

本文基于小光点扫描,在国内首次提出了一种测试小F数衍射微透镜阵列光学性能的方法.利用光通信用半导体激光器和探测器建立了一套测试系统,并对所研制的大阵列,小单元尺寸的多相位菲涅耳衍射微透镜阵列的衍射效率和点扩散函数进行了测试.结果表明,衍射微透镜实际衍射光斑比理论衍射受限光斑扩展不大,8相位和16相位石英微透镜的衍射效率分别高达80.2%和87.5%,说明本实验室对多相位的设计理论和制作工艺已基本掌握,满足应用的要求.     

一种新型微透镜阵列成象式投影光刻系统的研究

从理论和实验两方面入手,系统地研究了微透镜阵列的形成原理和制作工艺,分析了微透镜阵列的面形结构,得到了联系微透镜阵列矢高与制作工艺参量的经验公式.并且将四片微透镜阵列耦合,形成一个深紫外光刻的1:1成象的多孔径微小光刻系统.从几何光学理论出发,分析了这个光刻系统综合成象的特点,讨论了这种光刻系统的光学性能,并给出了实验测量方法.     

Diffractive Microlens Array Monolithic Integration with PtSi Focal Plane array

Diffractive microlens arrays can completely collect the light at the focal plane and concentrate it into a smaller spot size on the detector plane, the photodetector area can be substantially reduced. Increased gamma radiation hardening and noise reduction result from the decrease in photodetector sensitive area. The diffractive microlens arrays have been designed by considering the correlative optical and processing parameters for PtSi focal plane array. They have been fabricated on the backside of PtSi focal plane array chip by successive photolithography and Ar⁺ ion-beam-etching technique. The alignment of microlens array with PtSi focal plane array was completed by a backside aligner with IR light source. The practical processes and fabrication method are discussed. The performance parameters of PtSi FPA with diffractive microlens array are presented.     

Femtosecond laser microfabrication of periodic structures using a microlens array

A microlens array (MLA) was applied for femtosecond laser microfabrication. Two-dimensional periodic patterns that corresponded to the arrangement of lenses in the MLA were recorded by ablation on a glass surface. The two-dimensional periodic patterns were recorded by a single exposure without scanning of the laser beam or the sample, and worked as a grating. Optical resizing of the patterns and high efficiency of fabrication are demonstrated and discussed. PACS 42.82.Cr; 07.60.Pb; 42.62.Cf     

原子力显微镜加工红外微透镜阵列的研究

提出了利用原子力显微镜灰阶阳极氧化方法加工Si、Ge、GaAs等晶体材料为基础的红外微透镜阵列.加工了3×3的红外硅微透镜阵列,微透镜的高度和表面直径重复性误差分别为0.2nm和6.0 nm,微透镜的平均曲率半径为510.8 nm.分析了原子力显微镜加工红外微透镜产生面型结构误差的原因,并提出了减小面型结构误差的方法.利用此种方法加工的折射、衍射和混合红外微透镜阵列可以进一步缩小红外成像系统的尺寸.     

Imaging Properties of Planar Microlens Arrays

The planar microlens arrays is a two-dimensional array of optical component which is fabricated monolithically available. Imaging properties of planar microlens arrays are described, which provide both image multiplexer and erect, unit magnification images.