Large-field objective lens for multi-wavelength microscopy at mesoscale and submicron resolution

Conventional microscopes designed for submicron resolution in biological research are hindered by a limited field of view,typically around 1 mm.This restriction poses a challenge when attempting to simultaneously analyze various parts of a sample,such as different brain areas.In addition,conventional objective lenses struggle to perform consistently across the required range of wavelengths for brain imaging in vivo.Here we present a novel mesoscopic objective lens with an impressive field of view of 8 mm,a numerical aperture of 0.5,and a working wavelength range from 400 to 1000 nm.We achieved a resolution of 0.74μm in fluorescent beads imaging.The versatility of this lens was further demonstrated through high-quality images of mouse brain and kidney sections in a wide-field imaging system,a confocal laser scanning system,and a two-photon imaging system.This mesoscopic objective lens holds immense promise for advancing multi-wavelength imaging of large fields of view at high resolution.

Femtosecond laser 3D printed micro objective lens for ultrathin fiber endoscope

The most important optical component in an optical fiber endoscope is its objective lens.To achieve a high imaging performance level,the development of an ultra-compact objective lens is thus the key to an ultra-thin optical fiber endoscope.In this work,we use femtosecond laser 3D printing to develop a series of micro objective lenses with different optical designs.The imaging resolution and field-of-view performances of these printed micro objective lenses are investigated via both simulations and experiments.For the first time,multiple micro objective lenses with different fields of view are printed on the end face of a single imaging optical fiber,thus realizing the perfect integration of an optical fiber and objective lenses.This work demonstrates the considerable potential of femtosecond laser 3D printing in the fabrication of micro-optical systems and provides a reliable solution for the development of an ultrathin fiber endoscope.

The BL Lac Object PKS 0537-441: A Lens or Being Lensed?

We present and discuss deep high resolution images taken with the ESO NTT as well as spectra taken with the ESO VLT in the field of the BL Lac object PKS 0537 441. We could neither detect the host galaxy nor a galaxy along the line of sight to the BL Lac as claimed from previous observations. We found 4 nearby companion galaxies which could be a splitted and magnified image of a distant background galaxy. Our VLT spectra, however, rule out this possibility. All 4 companions have similar redshifts as the BL Lac and may (at least in part) trigger the enormous activity in this source. PKS 0537 441 might be located in a galaxy cluster as rich as Abell 1. Alternatively, the BL Lac could also be located in the outskirts of a galaxy cluster or even be projected on a large scale structure as indicated by spectra of 30 galaxies in the field. Either lensing hypothesis (lens or being lensed) is considerably weakened by our observations.

Evaluation of visual quality of spherical and aspherical intraocular lenses by Optical Quality Analysis System

AIM： To evaluate the impact of spherical and aspherical intraocular lenses on the postoperative visual quality of age-related cataract patients using Optical Quality Analysis System （OQAS）. METHODS： Seventy-four eyes with age-related cataracts were randomly divided into spherical and aspherical lens implantation groups. Best-corrected visual acuity （BCVA） was measured preoperatively, one day, one week, two weeks, one month and two months after surgery. A biometric systems analysis using the OQAS objective scattering index （OSI） was performed. RESULTS： There were no significant differences in visual acuity （P〉0.05） before and after spherical and aspheric lens implantation. There was a negative linear correction between the OSI value and BCVA （t-=-0.634, P=-0.000）, and positive corrections between the OSI value and the lens LOCUS III value of nucleus color （NC）, nucleus opacity （NO）, cortex （C） and posterior lens capsular （P） （r=0.704, P=0.000; r=0.514, P=0.000; r=0.276, P=0.020; r=0.417, P=-0.000, respectively）. OSI values of spherical vs aspherical lenses were 11.5±3.6 vs 11.8±3.4, 4.1±0.9 vs 3.3±0.8, 3.5±0.9 vs 2.7±0.7, 3.3±0.8 vs 2.6±0.7, 3.2±0.7 vs 2.5±0.8, and 3.2±0.8 vs 2.50.8 before and ld, 1, 2wk, 1 and 2mo after surgery, respectively. All time points varied significantly （P〈0.01） between the two groups. CONCLUSION： Aspherical IOLs does not significantly affect visual acuity compared with spherical IOLs. The OSI value, was significantly lower in the aspherical lens group compared with the spherical lens. This study shows that objective visual quality of aspheric IOLs is better than that of the spherical lens by means of OQAS biological measurement method.

Up-Sampled Cross-Correlation Based Object Tracking & Vibration Measurement in Agriculture Tractor System

This research introduces a challenge in integrating and cleaning the data,which is a crucial task in object matching.While the object is detected and then measured,the vibration at different light intensities may influence the durability and reliability of mechanical systems or structures and cause problems such as damage,abnormal stopping,and disaster.Recent research failed to improve the accuracy rate and the computation time in tracking an object and in the vibration measurement.To solve all these problems,this proposed research simplifies the scaling factor determination by assigning a known real-world dimension to a predetermined portion of the image.A novel white color sticker of the known dimensions marked with a color dot is pasted on the surface of an object for the best result in the template matching using the Improved Up-Sampled Cross-Correlation(UCC)algorithm.The vibration measurement is calculated using the Finite-Difference Algorithm(FDA),a machine vision systemfitted with a macro lens sensor that is capable of capturing the image at a closer range,which does not affect the quality of displacement measurement from the video frames.Thefield test was conducted on the TAFE(Tractors and Farm Equipment Limited)tractor parts,and the percentage of error was recorded between 30%and 50%at very low vibration values close to zero,whereas it was recorded between 5%and 10%error in most high-accelerations,the essential range for vibration analysis.Finally,the suggested system is more suitable for measuring the vibration of stationary machinery having low frequency ranges.The use of a macro lens enables to capture of image frames at very close-ups.A 30%to 50%error percentage has been reported when the vibration amplitude is very small.Therefore,this study is not suitable for Nano vibration analysis.

区域折射型人工晶状体对散光的包容性

目的:探讨年龄相关性白内障患者行白内障超声乳化摘除联合区域折射型人工晶状体(IOL)植入术后残余散光对视觉质量的影响,评估区域折射型IOL对散光的包容性。方法:回顾性队列研究。收集2020-07/2022-03于我院眼科行白内障超声乳化摘除联合区域折射型IOL(Lentis Comfort LS-313 MF15)植入术的年龄相关性白内障患者62例73眼的临床资料,根据术后6 mo残余散光度数进行分组,0.75 D<残余散光度数≤1.50 D的患者35例40眼作为试验组,残余散光度数≤0.75 D的患者27例33眼作为对照组。比较两组患者术后6 mo视力、离焦曲线、客观视觉质量[波前像差、斯泰尔比值(SR)、调制传递函数(MTF)]、主观视觉质量(视功能问卷评分)、满意度及脱镜率情况。结果:两组患者术前散光度数及术后6 mo残余散光度数均有差异(P<0.01)。术后6 mo,两组患者裸眼远、中、近视力、客观视觉质量、主观视觉质量、满意度及脱镜率均无差异(P>0.05),离焦曲线显示,两组患者在附加球镜度数+2.00--4.00 D离焦范围内各点视力均无差异(P>0.05)。结论:Lentis Comfort LS-313 MF15 IOL能够包容1.50 D以内的规则散光。

高精度线扫式光谱共焦位移传感器光学系统设计

光谱共焦位移传感器是一种新型几何量精密测量传感器,具有高精度,高效以及非接触的技术优势,目前被广泛应用于微观或宏观几何量的精密测量。传统的几何量测量传感器采用接触式机械探针,对物体表面造成损伤,难以满足现代化制造业无损测量的需求。不同于传统的光学系统需要校正轴向色差,光谱共焦位移传感器利用轴向色差建立位移和波长之间的关系。然而目前针对光谱共焦位移传感技术的研究大多集中于点扫式,仅能获取单个点位的几何量信息,在实际应用中需要较大区域的精密测量,故而效率受到极大的限制,并且对后端数据处理要求较高,数据重构较为繁琐。针对该技术弊端,设计出一种线扫式光谱共焦位移传感器系统,达到了亚微米的分辨率。对线扫式光谱共焦位移传感器进行原理分析,开展了大量程色散物镜、高光谱分辨率成像光谱仪的详细设计。通过对色散物镜和成像光谱仪光路结构的优化及像差的平衡,使得全系统各视场RMS半径小于5.5μm,得到了很好的成像质量。结果表明,全系统在扫描线长10 mm,轴向量程范围3 mm,分辨率达到0.8μm。该研究在高效、高精度几何量精密测量领域具有广阔的应用前景。

超声乳化术联合SBL-3区域折射型非球面IOL治疗年龄相关白内障的效果及对视觉质量的影响

目的 探究超声乳化术联合SBL-3区域折射型非球面人工晶状体(IOL)治疗年龄相关白内障的效果及对视觉质量的影响。方法 选取2022年1—12月收治的年龄相关白内障110例,采用随机数字表法分为单焦点组55例和SBL-3组55例,单焦点组予超声乳化术联合ADAPT AO非球面单焦点IOL植入,SBL-3组给予超声乳化术联合SBL-3区域折射型非球面IOL植入。比较2组术后3个月对比敏感度[明光、暗光、明光炫光、暗光炫光],术前和术后3个月视觉质量[客观散射指数(OSI)、斯特列尔比(SR)、调制传递函数截止频率(MTF cut off)]、视力[最佳矫正近视力(BCNVA)、最佳矫正远视力(BCDVA)、远视矫正下的近视力(DCNVA)]及生活质量[视功能与生存质量问卷(VF-QOL)]。结果 术后3个月,SBL-3组对比敏感度高于单焦点组(P<0.05);术后3个月,2组OSI、BCNVA、BCDVA、DCNVA水平均较术前降低,SBL-3组低于单焦点组(P<0.05);术后3个月,2组SR、MTF cut off水平及VF-QOL评分均较术前升高,SBL-3组高于单焦点组(P<0.05)。结论 超声乳化术联合SBL-3区域折射型非球面IOL能够提高年龄相关白内障患者对比敏感度及视觉质量,改善视力水平及生活质量。

基于改进YOLOv5s的曲面光学镜片缺陷检测

针对曲面光学镜片表面缺陷检测精度不高的问题,提出一种基于改进YOLOv5s的曲面光学镜片缺陷检测方法。首先,设计镜片表面缺陷采集装置,并对采集到的缺陷图片进行数据增强以制作镜片缺陷数据集。其次,为了增强YOLOv5s网络对通道信息的利用,在特征提取网络引入SE注意力机制,使网络能够更加准确地提取信息;并在主干网络最后一个C3模块融入Transformer,帮助网络更好地提取全局信息,提高检测效率。最后,考虑到小目标特征信息容易丢失的问题,将主干网络160×160像素的特征层加入颈部的特征融合中,增加网络对浅层信息的利用。改进的YOLOv5s目标检测算法的均值平均精度(mean average precision,mAP)和召回率(recall,R)分别为93.9%和91.6%,比原网络算法分别提高了3.2%和3.4%,表明改进YOLOv5s算法可以有效检测出镜片表面缺陷。

大景深显微镜的实现方式

大景深显微镜能够在不同焦平面上获取清晰的图像,为晶圆的对准提供了强大的支持。为了扩展景深,研究人员提出了多种技术,包括缩小系统孔径、波前编码和光学切趾等。提出了一种扩展景深的新方法,即双焦点物镜对准,该方法操作简单直观,并且可以直接采集对准标记来实现对准,从而极大地提高了对准的准确性和效率。这些技术和方法为大景深显微镜的后续研究奠定了坚实的基础。

基于光纤束传像系统的设计与加工研究

针对传统的传像系统易受电磁干扰的问题,设计并实现了在特殊环境下使用的光纤束传像系统。利用ZEMAX光学仿真软件,设计出了一个工作波段为可见光,全视场80°,焦距为5 mm的监控物镜。该物镜各视场光学调制传递函数(Modulation Transfer Function,MTF)值在空间频率36 lp/mm处大于0.8,点列图最大弥散斑均方根半径(RMSradius)为3.031μm,接近衍射极限,因此具有较高成像质量。采用加工的物镜、选型转接镜及光纤束等核心器件,搭建了传像系统。通过测试光纤束图像传输系统的抗电磁干扰性能,采用高斯低通滤波结合DCT同态滤波算法有效去除图像的像素,获得了高质量的信息传输效果。

超高真空光学显微系统的设计

电子显微镜等仪器是研究材料微观形貌的重要工具,常工作在真空环境。为了快速瞄准电子显微镜测量的目标区域,有必要引入一种辅助光学显微镜,直接提供样品区域的空间图像。文章介绍了一种用于超高真空环境直接观测的超高真空光学显微系统的设计,光学显微物镜具有21.8mm的长工作距离,实现了40倍的光学放大和实测横向1.28μm,纵向1.59μm的高分辨率成像,足以辅助多种电子显微类仪器装置搜索目标区域。该物镜分为两个镜组,其中前镜组在超高真空内,后镜组在超高真空外,前后镜组距离680mm,并通过真空六维调整架控制整个显微物镜对目标样品进行扫描,对改进电子显微镜的探测效率起到非常明显的效果。此外,该显微镜也可应用于真空机械剥离等其他需要光学辅助的系统。

基于掩膜相位板的鼻内镜成像优化研究

我国鼻内窥镜受加工,装调等因素的影响,内窥镜在实际使用时的分辨率及像差情况要明显差于设计水平,论文经过公差分析,得出偏心公差对结果影响巨大,基于以上问题,文章在设计的一款视场角为80°,入瞳直径为0.2mm的鼻窦物镜基础上,模拟装调误差,提出在不改变装调后鼻窦物镜机械结构的前提下,在物镜保护玻璃前方加入掩膜相位板补偿装调误差导致的成像质量下降;从设计结果可知,添加掩膜相位板后系统传函图从在空间频率30lp/mm等于0提升到170lp/mm大于0.2;用N3鉴别率板检测系统分辨率,物方可分辨18组左右,物方分辨率为15μm。由此可知在补偿掩膜相位板的设计中,在不改变原设计基础上,可明显提高像质。

大数值孔径宽光谱折反式物镜设计(特邀)

为了满足半导体缺陷检测系统对成像系统高分辨的要求,依据系统的特点和设计指标,设计了一种近紫外-可见光大数值孔径折反式物镜。在近紫外-可见光波段对光学玻璃材料的色散特性进行分析,通过二级光谱理论计算,选择合适的玻璃材料,对光学系统的二级光谱进行了校正。该物镜使用11片球面透镜,结构紧凑。设计出一套光谱范围为360~520 nm、数值孔径为0.9、焦距为5.65 mm、视场大小为0.8 mm、工作距离为0.8 mm的物镜,采用无限远共轭折反式结构。设计结果表明:该物镜的MTF较好,全视场波像差小于0.09λ(λ=632.8 nm),各种几何像差均得到了较好的校正,满足复消色差条件,并且结构简单,具有较长的工作距离,为实际的生产装配和应用提供了便利。

手机后置双摄像头暗角问题分析与改善研究

从实际生产问题出发,以开展QCC质量小组活动的形式对项目试产过程中出现的双摄像头客观测试Lens Shading暗角问题进行了全面的分析与研究。通过全面质量管理理论中的“人机料法环测”六大方面进行综合验证,并进行实际样机测试对比,最终得出引起问题的关键要因。

支撑应力对光刻透镜透射波前畸变的影响

为了设计光刻物镜的支撑结构,建立了支撑应力对透镜透射波前影响的模型,研究了该模型中支撑应力与折射率的关系及支撑应力对透镜透射波前畸变的影响。首先,根据晶体理论,建立了融石英透镜波前畸变与支撑应力之间关系的仿真模型。然后,分析了不同支撑结构下支撑应力与融石英透镜波前的关系。最后,分析了支撑应力造成的透射波前畸变的性质,并选择合适的物镜支撑结构。研究结果表明:光刻物镜支撑结构的支撑应力对透镜的透射波前有很大的影响:3点支撑的波前畸变PV值为3.69 nm;随着支撑点数量的增加,支撑应力造成的透射波前畸变逐渐减少;采用大于9点的支撑结构即可满足光刻投影物镜的元件支撑需求。

具有整体径向挠性的光学元件多点均匀支撑结构

光刻投影物镜中透镜的面形精度是影响光学系统成像质量的关键因素之一。为满足透镜面形精度RMS值优于1~2 nm的指标要求,本文提出了一种具有整体径向挠性的透镜多点均匀支撑结构,基于自重变形和热变形对支撑块尺寸进行了优化设计,分析了透镜在优化后的支撑结构下由自重和热载荷引入的面形变化情况,结果表明：自重引起的透镜上表面面形去除power项后RMS为0.429 nm,下表面面形去除power项后RMS为0.294 nm;热载荷引起的透镜上表面面形RMS为0.409 nm,下表面面形RMS为0.063 nm,能够满足光刻投影物镜中透镜的高精度面形要求。

利用光纤传像束的内窥镜物镜设计

光纤传像束用于内窥镜时,对内窥镜物镜的结构型式和成像质量提出了新的要求。在分析了其基本设计原则后,根据实际需求,选用反远距型物镜作为初始结构,利用Zemax软件优化设计了一个工作波段0.38~0.78μm,焦距0.921 mm,全视场100°、相对孔径1/4的内窥镜物镜。镜头总长10.32 mm,满足像方远心要求,在38 lp/mm频率处MTF值在0.85以上,像质优良;同时,在Tracepro软件中建立了所设计物镜与光纤传像束结合后系统的模型,模拟的系统耦合效率约为96%且出射端照度均匀。结果表明：该物镜具有视场大、短焦距、结构合理、耦合效率高、像面照度均匀等特点,满足内窥镜要求。

推扫式红外光纤传像光学系统研究

针对推扫式红外遥感成像技术在高分辨对地观测领域的重要地位,结合我国红外遥感技术发展现状和长线阵红外探测器技术水平,研究了利用线面转换的异型红外光纤传像束线阵端实现推扫,面阵端与成熟的小面阵红外探测器耦合以获得高分辨红外遥感图像的光纤传像系统.分析了该红外光纤传像系统前置物镜和耦接镜设计中的主要问题,并针对一种入射端为4 000×6元线阵,出射端为160×150元面阵的红外光纤传像束设计了前置物镜系统和后继耦接镜系统.引入平均传递函数的方法对整体光学系统的MTF进行了模拟评价,模拟结果显示整体光学系统成像良好,两系统的成像性能皆达到衍射极限,满足光纤传像系统的特殊要求,可为该类光纤传像系统的设计提供参考.

一种新型复合摄像物镜的设计

讨论了一种新的双高斯型与Topogon型复合的光学系统。新型结构是在传统结构的基础上,于光阑附近增加一个光焦度不大的负薄透镜,降低了系统的高级负球差,减小量为-0.079 4,而增加的-0.110 7的高级负像散与初始设计的高级正像散抵消,并产生了-0.068 2的高级负场曲抵消原有的正场曲,使像散和场曲的校正得到明显改善,成像质量显著提高,特别是1视场MTF从0.112提高到0.493。