微透镜列阵与红外探测器列阵集成芯片的研究

在分析微透镜列阵光聚能原理的基础上,针对背照式256290铂硅红外焦平面探测器列阵 的结构参数,设计了衍射微透镜列阵,使入射光通过硅基底聚焦至探测器的各个光敏面上, 提高光能利用率从而增强探测能力。实验获得了微透镜列阵与红外焦平面集成芯片,并在热成像中取得了良好的结果。     

衍射微透镜列阵掩模制作软件的设计

研究了衍射微透镜列阵的设计方法及ＣＩＦ格式掩模数据的数据结构与生成方法,设计了一套产用软件,采用图形切割、跟踪计算等方法,解决了生成子孔径为矩形、六 方形及圆环扇形的衍射微透镜列阵掩模的问题,满足了实际系统对衍射微透镜列阵子孔径形状的各种需求。     

用于投影曝光微细线条的自动调焦调平系统

本文从投影光刻工艺的特殊要求出发,简要分析了在投影分步重复光刻机上配用自动调焦及调平系统的重要意义,着重介绍了两个光电式自动调焦、调平系统的原理、实验结果及主要特点。原理性实验结果表明,用两系统检测各种光刻过的晶片,都能得到小于0.2微米的离焦量和小于10秒(0.5微米/10毫米)的楔度的灵敏度,这能满足各种精细投影复印机的要求。     

基于无参考结构清晰度的自适应自动对焦方法

针对自动对焦系统,提出了一种基于单帧图像无参考结构清晰度的自适应变步长爬山搜索策略.该方法利用了无参考结构清晰度可提供的离焦量先验信息:当离焦量大时,大步距粗调快速逼近准焦位置;当离焦量小时,小步距微调准确定位准焦位置.该方法在不降低调焦精度的情况下,大大减少了自动对焦所需的图像数量和决策次数.实际系统实验结果表明,新...     

面向微加工的虚拟光刻系统建模与实现

提出了一种面向微加工的虚拟光刻系统Litho3D.该系统采用傅立叶光学成像模型、光刻胶曝光及显影模型,实现了投影式光学光刻的三维模拟.它拥有标准的GDSII、CIF版图格式接口和支持各种光学参数(包括数值孔径、波长、离焦量,光刻胶厚度、表面折射率等)的模拟设置.模拟结果的显示采用了体绘制与网格相结合的方法,增强了结果的可视性.此外,光刻模拟结果可以直接导入到虚拟工艺系统ZProcess中作为刻蚀工艺的掩膜输入,实现了光刻工艺与其他微机电系统(MEMS)工艺模拟的无缝集成.一系列模拟结果验证了该系统的可行性.     

用于纳米光刻的超分辨缩小成像平板超透镜研究

本文提出和研究了利用超分辨缩小成像平板超透镜,在i线光源波长下实现纳米尺度光刻方法.为了在超 分辨透镜像面位置获得高质量的光刻图形,采用超分辨透镜-光刻胶-反射银膜的结构方式,解决由于超透镜磁场偏振传输模式带来的成像光场畸变问题,大大提高了成像质量和光场对比度.采用掩模图形结构预补偿的方法,消除超分辨透镜的倍率畸变像差...     

形成连续微光学元件的灰度掩模图形生成方法

针对利用灰度掩模制作连续微光学元件的方法 ,介绍了从元件结构到灰度图形的转换 ,灰度图形的修正 ,灰度图形的数字化以及图形编码等关键步骤。最后给出生成微透镜列阵掩模图形的实例。     

湿法制作连续微透镜列阵新方法

制作连续微透镜列阵中主要的问题就是浮雕的深度和浮雕面形的控制,已有的微透镜列阵制作方法不能很好地解决;本文提出了一种利用干法和湿法蚀刻结合在硅片上制作连续深浮雕微透镜列阵的新方法,得到了深度４０μｍ的微柱面和旋转抛物面微透镜列阵。     

基于微透镜阵的外腔谱组束系统光束质量分析

针对基于微透镜阵的光纤激光外腔谱组束系统的光束质量评价问题,利用高斯光束的传输变换理论,建立了评价谱组束激光光束质量的理论模型.通过数值模拟,详细分析了各相关参数对谱组束光束质量的影响,结果表明:在基于微透镜阵的谱组束系统中,离焦量、微透镜焦距及模场半径是影响谱组束激光光束质量的主要因素;阵列宽度对谱组束激光光束质量影...     

微透镜列阵衍射效应所致的串扰

本文分析了微透镜列阵衍射效应的影响因素,推导出了微透镜焦平面上光强分布的解析表达式,对菲涅尔数评价衍射效应的物理含义给予了合理的解释.并利用ZEMAX软件对微透镜列阵进行仿真,基于惠更斯子波直接积分的算法计算得到了微透镜列阵焦平面上的光场强度分布.通过比较不同条件下所得到的计算结果,验证了以菲涅尔数作为微透镜列阵衍射效应评价依据的的合理性,同时验证了以菲涅尔数判断焦斑间串扰的可行性.     

Design and fabrication of a freeform microlens array for a compact large-field-of-view compound-eye camera

In this research, a unique freeform microlens array was designed and fabricated for a compact compound-eye camera to achieve a large field of view. This microlens array has a field of view of 48°×48°, with a thickness of only 1.6 mm. The freeform microlens array resides on a flat substrate, and thus can be directly mounted to a commercial 2D image sensor. Freeform surfaces were used to design the microlens profiles, thus allowing the microlenses to steer and focus incident rays simultaneously. The profiles of the freeform microlenses were represented using extended polynomials, the coefficients of which were optimized using ZEMAX. To reduce crosstalk among neighboring channels, a micro aperture array was machined using high-speed micromilling. The molded microlens array was assembled with the micro aperture array, an adjustable fixture, and a board-level image sensor to form a compact compound-eye camera system. The imaging tests using the compound-eye camera showed that the unique freeform microlens array was capable of forming proper images, as suggested by design. The measured field of view of ±23.5° also matches the initial design and is considerably larger compared with most similar camera designs using conventional microlens arrays. To achieve low manufacturing cost without sacrificing image quality, the freeform microlens array was fabricated using a combination of ultraprecision diamond broaching and a microinjection molding process.     

单层曲面复眼成像系统的优化设计

与传统曲面复眼结构不同,提出了在曲面基底上设计非均一微透镜阵列的构想.整个透镜阵列呈环状对称分布,沿径向排列的各级透镜其焦距由所处位置决定,与基底到光探测阵列的距离相吻合.根据几何光学成像原理计算了各级透镜的设计参数并通过光线追迹加以验证.仿真结果表明,这种设计可对全视场在光探测阵列上聚焦,解决了传统曲面复眼边缘视场成像质量急剧下降的问题.同时还论证了采用光刻胶热熔法在曲面基底上制作非均一微透镜阵列的可行性.     

振幅分割无掩模激光干涉光刻的实现方法

无掩模激光干涉光刻中的分束方法一般有波前分割和振幅分割。研究和比较了振幅分割无 掩模激光干涉光刻方法和系统,包括振幅分割双光束干涉系统、三光束干涉系统、液浸式深紫外干涉系统及全自动干涉光刻系统。建立了双光束双曝光干涉光刻实验系统。模拟和实验结果表明,对点阵或孔阵图形,在同样的图形尺度下,无掩模干涉光刻比传统光刻简单得多。     

Replication of Microlens Arrays by Gas-Assisted Hot Embossing

This article reports an effective method for mass-production of 300 × 300 microlens arrays. A microlens array master is formed by imprint lithography and photo-resist reflow at room temperature. The electroforming is then applied to fabricating the Ni mold from the master, followed by the gas-assisted hot embossing to replicate the microlens arrays. The isotropic gas pressure on the plastic film against the Ni mold produces plastic microlens array of high quality and uniformity. The effects of processing parameters including the processing temperature, pressure, and time on the replication quality of microlens arrays were investigated. The experimental results show that the filling of molded microlens significantly increases as the processing temperature and pressure increase. Under the condition of 180°C, 3.9 MPa for gas pressure, and 90 seconds processing time, the arrays of polycarbonate microlens of diameter 150 µm and pitch 200 µm have been successfully replicated. The deviation of replicated microlens from the mold is less than 0.25%. Compared with the conventional hot embossing process, the new replication method offers more uniform embossing pressure distribution. The great potential for replicating microlens array on large plastic films with high productivity and low cost was demonstrated.     

用灰度曝光技术改善数字光刻图形轮廓

基于空间光调制器(SLM)数字光刻技术可用于IC掩模制作或直接作为微结构的加工工具,但用数字投影光刻系统加工某些结构的二元图形时,往往难以获得预期的图形轮廓,即图形边缘处有一定畸变,特别是较低缩小倍率时。本文提出优化设计图形边缘灰度的方法来校正光刻图形的畸变。文中分析了数字光刻制作这些二元光刻图形时空间像畸变产生的物理机制,详细讨论了设计图形边缘灰度优化的规则,并以加工圆孔滤波器为例,模拟了它的数字光刻成像过程。结果表明,设计图形的边缘采用灰度曝光可使其空间像畸变减小约8个百分点,光场分布更为均匀。数字灰度曝光技术简单易行,可为改善光刻图形质量提供了新途径。     

微透镜阵列对Hartmann—Shack波前探测器探测精度的影响

微透镜阵列是Ｈａｒｔｍａｎｎ－Ｓｈａｃｋ波前探测器的核心元件之一。本文从理论上分析了微透镜阵列的性能对Ｈａｒｔｍａｎｎ－Ｓｈａｃｋ波前探测器的波前探测精度的影响，并根据理论分析进行了一系列实验，得到了有益的结果。     

Speckle-reduced three-dimensional volume holographic display by use of integral imaging

We propose a method to implement a speckle-reduced coherent three-dimensional (3D) display system by a combination of integral imaging and photorefractive volume holographic storage. The 3D real object is imaged through the microlens array and stored in the photorefractive crystal. During the reconstruction process a phase conjugate reading beam is used to minimize aberration, and a rotating diffuser located on the imaging plane of the lens array is employed to reduce the speckle noise. The speckle-reduced 3D image with a wide viewing angle can be reconstructed by use of the proposed system. Experimental results are presented and optical parameters of the proposed system are discussed in detail.     

Variable Focusing Microlens Chip for Potential Sensing Applications

A variable focusing microlens chip, which has the capability of adjusting its focal length over a wide range without any mechanical driving parts, is reported in this paper. The packaged microlens chip consists of a flexible polymer lens, a fluidic chamber, an integrated sensor, and an actuator. A thermal actuator is introduced into this variable focusing microlens to obtain relatively large actuation force and displacement. The hemispheric convex polymer lens provides an initial focal point without being actuated. The focal length change is controlled by varying the voltage applied to the thermal actuator. A 1.9-mm-diameter polymer lens is made to test the performance of the device. The focal length of this chip varies from 14.658 to 2.782 mm, which corresponds to the change of numerical aperture from 0.078 to 0.412. Based on the working mechanism and constructing method of the single lens chip, a variable focusing microlenses array has been fabricated for future testing and application. Potential sensing applications for single lens and array include cell detection and immobilization, optical sensors, lab-on-a-chip, ophthalmic lens systems, microphotonics, high throughput scanning, and confocal imaging system