交叉非对称型Czerny-Turner光谱仪光学系统设计

根据Czerny-Turner结构光谱仪工作原理,以便携式微型光学系统为设计目标,设计了一种光谱范围为200900nm的交叉非对称型Czerny-Turner光谱仪光学系统.通过分辨率、光谱范围等设计要求确定光谱仪大致结构后,引入初级像差对初始结构进行进一步优化.首次提出将球差约束条件与光阑面选取相结合,设计流程确定准直镜通光口径、光栅初始尺寸及聚焦镜中心波长对应口径,继而结合彗差约束条件,确定球面镜离轴角,并基于几何光学确定聚焦镜初始通光口径的方法.利用ZEMAX软件对初始参量进行模拟优化,并采用自主研制的样机进行光谱测量,分析结果表明,该光学系统能够在狭缝宽度为25μm,光栅常数为1.667μm/line条件下,实现中心波长分辨率优于1nm,边缘波长分辨率优于1.5nm.     

指纹及手指静脉图像复合采集光学系统设计

针对生物特征的多模识别技术,设计了一款用于指纹及手指静脉图像复合采集的光学系统。用于采集指纹和手指静脉图像的光学镜头分别由3片和12片球面透镜构成,工作波长分别为650 nm和850 nm,成像器件分别采用640 pixel×480 pixel CCD和640 pixel×512 pixel非制冷红外探测器。使用Zemax软件对该系统的光学结构进行了设计和优化。像质评价结果表明:指纹图像采集镜头在空间截止频率67 lp/mm处,调制传递函数MTF值大于0.6;手指静脉图像采集镜头在空间截止频率30 lp/mm处,调制传递函数MTF值大于0.8;两镜头各视场弥散斑均方根半径远小于成像器件像元尺寸,接近衍射极限,且成像畸变均小于0.5%。实验证明该系统采集到的图像质量优良,分辨率高。     

i线投影光刻曝光系统的光学设计

叙述具有同轴对准特性的光学投影物镜双远心结构和均匀照明光学系统原理。为了满足ｉ线光刻所需的光学传递函数要求，讨论了光刻分辨率和数值孔径的关系。设计了一种新的双远心投影物镜，其数值孔径ＮＡ＝０．４２，放大倍率Ｍ＝－１／５，像场尺寸１５ｍｍ×１５ｍｍ（直径２１·２ｍｍ），共轭距Ｌ＝６０２ｍｍ。用光学设计程序ＺＥＭＡＸ－ＸＥ计算此ｉ线物镜的像质。设计结果说明，整个视场内波差＜λ／４，ＭＴＦ＞０．５５，当空间频率为７１５ｐａｉｒｌｉｎｅｓ／ｍｍ，使用波长为３６５士３ｎｍ时。可以实现０．７μｍ光刻分辨率；照明均匀器，由８１个小方型透镜组成一方列阵。用本文模拟计算软件ＯＰＥＮＧ计算被照像平面上的光能分布，说明实际系统的照明不均匀性为土２％。     

High-resolution optical coherence tomography over a large depth range with an axicon lens

In optical coherence tomography, axial and lateral resolutions are determined by the source coherence length and the numerical aperture of the sampling lens, respectively. Whereas axial resolution can be improved by use of a broadband light source, there is a trade-off between lateral resolution and focusing depth when conventional optical elements are used. We report on the incorporation of an axicon lens into the sample arm of an interferometer to overcome this limitation. Using an axicon lens with a top angle of 160 degrees , we maintained 10-microm or better lateral resolution over a focusing depth of at least 6 mm. In addition to having high lateral resolution, the focusing spot has an intensity that is approximately constant over a greater depth range than when a conventional lens is used.     

A liquid lens-based broadband variable fiber optical attenuator

To the best of our knowledge, proposed is the first variable fiber optical attenuator (VFOA) using an electronically controlled variable focus liquid lens. The approach uses the changes in the radius of curvature of the liquid lens edge to enable an electronically controlled optical wedge that produces a varying beam tilt angle. In effect, changing beam tilt within a single mode fiber (SMF) lens free space coupling assembly leads to a polarization independent broadband VFOA design. The demonstrated VFOA experiment shows broadband operation over the 1530-1560 nm C-Band with a 40 dB dynamic range, <0.5 dB resolution, 0.3 dB polarization dependant loss, 4.3 dB fiber-to-fiber optical loss, 3 dB optical bandwidth from 1510 nm to 1700 nm, and switching time of <100 ms. Applications for this VFOA include use in hand held test and measurement equipment.     

宽视场高分辨率闭路监控系统监控镜头设计

为了满足新形势下闭路监控系统（CCTV）对拍摄视场和高清分辨率的要求,设计了一款复杂化的反摄远型全球面结构的CCTV镜头。该镜头的全视场为80,F#为3,焦距为5 mm,光谱范围为486 nm~656 nm。采用像元尺寸为7.5 m7.5 m,1.27 cm(1/2英寸)的CCD成像。该镜头在奈奎斯特频率67 lp/mm处,全视场MTF接近0.65;在1/2奈奎斯特频率处调制传递函数（MTF）大于0.85;在220 lp/mm处,全视场MTF大于0.3,已经接近衍射极限。镜头像面波前PV值为0.077 9,RMS为0.015 9,达到了瑞利判据的要求。设计评价结果表明,该镜头像差校正满足CCTV监控镜头的成像质量要求。     

微型差动式共焦自聚焦光聚焦探测系统

为解决微小内轮廓尺寸为代表的微小尺寸的非接触式超精密测量问题，提出了将自聚焦透镜体积小的特点与共焦显微技术的高分辨率和绝对位置跟踪特性相结合的差动式自聚焦共焦微型显微技术的光探测技术，建立了相应的传感系统，介绍了系统的工作原理和构成，自聚焦透镜测头直径为1mm，两个探测器差动设置，不但消除了光源的光强漂移和探测器的电子漂移产生的共模噪声，提高了测量信噪比，而且有效地提高了系统的轴向分辨率，初步实验表明，系统轴向分辨率在倾斜率小于20度的范围内可达5nm。     

水下气泡高速摄影光学系统设计

为了研究水下气泡的粒径、速度和浓度特性,提出基于高速电荷耦合器件(CCD)的气泡照明和三维摄影光学系统.采用532nm半导体激光器,基于伽利略结构用三个柱面镜设计了厚度1.5mm,宽度44mm的片光源。设计物像距530mm,放大率为0.4,1,2.5倍(×)的摄影光学系统,每组均由共用前组镜和会聚镜组成,中间以平行光中继。通过同步移动片光源和共用前组镜实现60mm×40mm视场内二维高速成像和纵向5mm扫描,具有结构简单、性能可靠的特点。对设计结果进行评价,0.4,1,2.5×成像光学系统在0.707ω,50lp/mm时调制传递函数值分别为0.58,0.55和0.38,能够分辨粒径范围为10～450μm的气泡。     

棱镜-光栅-棱镜型光谱成像系统光学设计

为实现成像光谱仪系统的直视性和小型化特点,设计一种棱镜-光栅-棱镜（PGP）结合式元件,作为分光系统的成像光谱仪光学系统装置。系统主要包括PGP分光原件、准直系统、成像系统和接收系统。光栅采用体全息相位光栅,可以获得很高的衍射效率,准直和成像镜采用对称式结构,可以有效地消垂轴像差。根据实际指标探测器像元尺寸为20 m20 m,像元数为512512,采用双像元合并方法,光谱通道数为148个,狭缝大小为10.2 mm10.2 mm,波段在400 nm~800 nm,物方数值孔径为0.15。分析了PGP光谱成像系统的原理、特点,对参数关系和体全息相位型光栅的衍射效率进行了详细的讨论。分析结果表明:PGP元件在整个光谱范围内理论衍射效率大于0.6,采用ZEMAX软件进行优化设计,得到系统的平均光谱分辨率优于3 nm,在截止频率处平均传递数大于0.7,系统总长90 mm。     

强激光装置中玻璃疵病在线检测的光学系统设计

介绍了一种用于玻璃疵病在线检测的近摄工作距成像光学系统,其光组结构形式采用了光阑后置的准远心结构形式,主要光学参量为f′=14 mm;在物像距为250 mm约束条件下,物方视场达到90 mm（对角线）;F/number=3.56;光谱适应范围为400~800 nm,对应的空间分辨率为100 lp/mm时,调制传递函数大于0.29.     

激光共聚焦近红外荧光扫描系统光学设计

为了实现对近红外荧光的高分辨率扫描,设计了工作在近红外光谱区的激光共聚焦光学系统。采用结构简单的凹凸双透镜物镜实现了照明光路和发射光路的设计,并采用Zemax软件进行了光学设计和仿真。实验表明:照明光路的聚焦弥散斑小于1 m,照明针孔处的聚焦光斑小于40 m,满足照明针孔的尺寸要求;发射针孔处的聚焦光斑小于10 m,满足探测针孔尺寸要求;同时照明光路和发射光路的MTF曲线的截止频率都分别满足其衍射极限分辨率的要求,照明光路在全视场空间分辨率420 lp/mm处MTF0.08,发射光路在全视场空间频率400 lp/mm处MTF0.07。     

Focus depth characteristics of lenses with long focal depth designed by a focal depth function

The validity of a focal length function is investigated in designing optical element with long focal depth and high lateral resolution. The designed lenses with different starting focal length are studied. Two focusing performance measures, focal depth and lateral resolution, are presented. Comparing with the conventional lens and optical element designed by other focal length function, numerical results of the designed optics element indicate that the long focal depth and high lateral resolution are achieved. The validity of the focal length function is confirmed. Meanwhile, the designed optical element is similar with the lens with spherical aberration. It means that one can easily implement long focal depth by applying appropriate phase modulation to a lens with spherical aberration.     

超大规模集成电路光学光刻技术的现状与展望

光学光刻是目前超大规模集成电路(VLSI)制备中主要的微米和亚微米的图形加工技术,这一技术将继续保持其主导地位成为90年代VLSI发展的关键。本文综述了近年来光学光刻工艺的发展,主要介绍了G线(436nm)、Ⅰ线(365nm)和准分子激光光刻的现状,并对实现高的光学光刻分辨率所必须解决的透镜设计、套准精度和像场面积等问题作了详细描述。最后展望了发展方向、     

拉曼光谱编码的荧光液相生物芯片检测系统研究

随着医疗诊断需求的增加,生物分子检测技术越来越受到人们的重视,液相生物芯片技术作为一种高通量,多通道的分子检测手段在近几年得到了飞速发展。通过层层自组装方法制备以微片为载体的拉曼光谱编码液相生物芯片,并利用自行搭建的一套高灵敏度、高分辨率的光学系统,实现对液相生物芯片的定性与定量分析。光学系统由拉曼光谱检测系统与荧光显微成像系统耦合而成。在拉曼光谱检测系统中激光器发射出785 nm波长的激光,通过二向色镜,带反反射镜与物镜汇聚到样品上,样品产生的拉曼散射光,经物镜,带反反射镜,二向色镜与拉曼滤波片,最后通过凹透镜聚焦到光谱仪的狭缝上,光谱仪色散实现在线阵CCD上拉曼光谱的获取。荧光显微成像系统应用光学成像原理,通过调节凹透镜与405 nm的激发光之间的距离,使激发光通过物镜均匀的照射到样品之上,样品激发出的荧光,通过物镜,带反反射镜,二向色镜,滤波片与相应的凹透镜,最后成像到面阵CCD上。改进传统便携式拉曼光谱检测系统光路并选用相应波段的带反反射镜与焦距20倍的物镜完成拉曼光谱检测系统与荧光显微成像系统的耦合。为了减少两路系统之间的相互影响选用合适的二向色镜以及滤波片,在提高耦合系统获取数据的准确性中有着重要的作用。该系统通过对反应之后的液相生物芯片进行拉曼光谱检测,以完成对每个编码玻片的定性识别,即解码;同时激发反应后液相生物芯片的荧光并采集荧光强度图,根据每个解码玻片上的荧光强度值完成对目标检测物的定量分析。区别于传统荧光编码液相生物芯片, 拉曼光谱编码具有稳定性更强,光谱分辨率更高等优点。该光学系统集拉曼光谱检测系统与荧光显微成像系统于一体,解决了目前未有基于拉曼编码的液相生物芯片的检测系统的问题,并且可同时对多种目标物进行识别和定量分析,提升了实验结果的准确性。     

紫外宽光谱大相对孔径光学系统设计

现有大部分紫外光学镜头的工作带宽较窄,紫外镜头的材料相对较少,镜头的紫外色差校正困难,导致其应用适应性降低.采用负正透镜交叠分布与类双高斯对称式结构形式,并利用熔石英材料和氟化钙材料本身的宽光谱透过性,设计了一种兼具大相对孔径、宽视场和高分辨率的紫外宽光谱光学系统.该系统的工作波长范围为240 nm～360 nm,紫外...     

小型高光谱分辨率光栅单色仪的研制

单色仪是成像光谱仪进行光谱连续定标的必备设备,为了对高光谱成像光谱仪进行连续光谱定标,设计了一种轻小型高光谱分辨率的光栅单色仪。采用水平式Czerny-Turner光路结构,以高光谱分辨率为出发点,通过推导计算,从光栅选型、焦距计算、狭缝尺寸的确定等方面详细论述了光栅单色仪的设计思路,给出仪器的重要必要结构参数,并论述了这些结构参数对仪器光谱分辨率和体积的影响。根据光栅单色仪的光路特点,对入射狭缝组件、准直物镜组件和成像物镜组件、扫描结构、机身等进行轻小型机械结构设计,并给出正弦杆扫描机构的结构参数与仪器输出波长和波长扫描精度的数学关系,完成了仪器的整体结构设计和装调。应用汞灯可见光光谱进行波长定标,采用最小二乘法得到定标曲线,并提出步进数极限误差与定标曲线相结合的方法,求得仪器的波长重复性和波长准确度;仪器在400~800 nm波长范围内,光谱分辨率优于0.1 nm,波长重复性达±0.096 6 nm,波长准确度达±0.096 9 nm。     

Axial coding in full-field microscopy using three-dimensional structured illumination implemented with no moving parts

We report a simple optical setup to produce both axial and lateral structured illumination through a single objective lens. With a minimum of six full-field images obtained without moving either the sample or the microscope objective, 100 nm diameter fluorescent beads can be localized axially with an accuracy of 50 nm in a 1.76-microm-thick layer. We show that this axial localization improvement can easily be combined with classical lateral structured illumination, so that lateral resolution enhancement by a factor of 2 is maintained.     

基于菲涅耳透镜阵列的红外气体传感器

菲涅耳透镜同时具有分光与会聚特性, 且体积小、重量轻和易复制, 使其在光谱检测中得到逐步应用, 但典型光谱成像仪采用菲涅耳透镜沿光轴扫描的方法来获得连续谱线, 不利于光谱仪的稳定性。考虑到气体探测需求, 选用多通道方式来获得多光谱, 提出了一种基于菲涅耳透镜阵列的新型红外气体传感器, 可实现吸收波长在3～5 μm的CO2,CO,CH4,SO2气体的实时检测。利用球面波的传输理论和瑞利判据, 推导了菲涅耳透镜光谱分辨率与透镜结构参数之间的函数关系, 并以光谱分辨率小于50nm为性能指标, 对1μm工艺的8台阶菲涅耳透镜阵列的结构参数进行了计算和误差分析。结果表明, 透镜阵列所需焦距为47.84 mm, 平均数值孔径大于0.4。     

Demonstration of a no-moving-parts axial scanning confocal microscope using liquid crystal optics

For the first time, to the best of authors’ knowledge, a no-moving-parts axial scanning confocal microscope (ASCM) system is designed and demonstrated using a combination of a large diameter liquid crystal (LC) lens and a classical microscope objective lens. By electrically controlling the 5 mm diameter LC lens, the 633 nm wavelength focal spot is moved continuously over a 48 μm range with a measured 3-dB axial resolution of 3.1 μm using a 0.65 numerical aperture (NA) micro-objective lens. The ASCM is successfully used to image an Indium Phosphide (InP) twin square optical waveguide sample with a 10.2 μm waveguide pitch and 2.3 μm height and width. Using fine analog electrical control of the LC lens, a super-fine sub-wavelength axial resolution of 270 nm is demonstrated. The proposed ASCM can be useful in various precision three-dimensional (3D) imaging and profiling applications.     

Experimental generation of high-contrast Talbot images with an ultrashort laser pulse

A femtosecond Ti:sapphire laser oscillator emitting pulses with 800 nm central wavelength, 10.9 fs pulse width, and 75 MHz repetition rate, combined with a dispersion-compensated diffractive system, was used to implement a large-area, high-contrast, broadband optical interference technique based on the Talbot effect. Chromatic artifacts associated with the huge spectrum of the optical source (approximately 150 nm) are compensated for with an air-separated hybrid diffractive-refractive lens doublet. The spatial resolution of the chromatically compensated Talbot images under femtosecond illumination is nearly identical to that achieved under continuous wave monochromatic illumination. Furthermore, the temporal width of the signal at the Talbot planes is limited by the group-delay-dispersion coefficient which is shown to be small. High-contrast one-dimensional periodic structures of 96.1 μm spacing generated by Talbot diffractometry are experimentally demonstrated.