高倍率大景深显微镜照明系统设计

本文从物理光学的部分相干光的干涉和衍射理论出发,对非相干光源成象的复相干度进行计算,得出在照明系统的出瞳上产生相干照明和非相干照明的条件。然后计算出相干照明、非相干照明以及部分相干照明时,显微镜象平面的强度I(P′)。通过对不同的m值的I(P′)计算,得出减少衍射效应的最佳结构参数,即:m=0.75时,象的边缘强度变化最小,分辨率最高,从而扩大显微镜的景深。这个分析结果已经得到实际验证。     

光刻的衍射极限

本文从菲涅尔衍射模型出发,在部分相干条件下对集成电路制造工艺所常用的光刻法的原理性限制作了研究。对于接触法光刻技术,本文给出了选择合理间隙的判据。关于投影光刻技术,通过直边衍射理论的计算和实验,得到照明相干度和调焦方式对边缘锐度的影响;发现目视调焦与光电瞄准两者在几何位置上的差别。这些结果也可适用于电子束光刻技术,从而有助于大规模集成电路的研制。     

光学传递函数(OTF)标准化进展情况

非相干成象系统的光学传递函数(OTF)描写了衍射和除畸变以外的各种象差对成象的影响.OTF的测量已被普遍认为是检验光学系统成象质量的主要项目.根据OTF制订的质量指标已经开始应用于照相物镜,电视、电影摄影物镜、航摄物镜等各类成象光学系统,评价设计结果,控制产品质量.     

纤维光学内窥镜的光学系统设计

本文介绍了纤维光学内窥镜的光学系统,包括观察系统、摄影系统、照明系统和教学系统,叙述各部分系统的成象原理。着重讨论內窥镜物镜的设计要求,以及镜头与传象束匹配中应注意的问题。     

部分相干照明条件下物镜表观传递函数的测定

本文介绍了一种测量部分相干照明条件下表征物镜对基频响应的表观传递函数的方法。这种方法是将干涉仪得到的出瞳处波面的干涉图用Zernike圆多项式逼近,求得波差函数。然后根据部分相干理论计算出表观传递函数。     

柱面波照明的周期性物体Talbot效应的研究

研究柱面波照明的周期性物体的自成象现象,推出了光场分布的表达式。由于物体的自成象不仅周期有变化,而且方向也改变,故分析了其自成象和另一块光栅形成的莫尔条纹的特点。     

单机立体图象显示仪的研制

本文论述了单机立体图象显示仪的成象原理和光学系统的设计方法，并给出了光学系统的结构参数。实践结果证明，这种方法是可行的精确的。     

对OTF测定仪光学系统的要求

本文叙述了在OTF测定仪中为了保证一定的测量精度对光学系统各组分应作如何要求。还讨论了非相干照明的条件,窄带滤光片的带宽和扫描光栅的精度要求。     

新产品新成果

<正> 适应高技术要求的光学性能系统互补术研究由上海光学仪器研究所承担的“适应高技术要求的光学性能系统互补术研究”课题,于今年6月通过了上海市科委级鉴定。该课题系上海市自然科学基金项目。主要研究开发光学系统照明、成象、放大三部分各部分的处理能力,在此基础上得到能满足光学上特殊要求的通用光学系统。它提供了一种光学系统结构无大变动、系统明显改善(如图象信噪比、分辨率、焦深成倍增大)的系统互补技     

利用全息成像系统实现非相干成像

相干激光束应用在全息成像系统的制作中。这项研究目的是,也把这类系统用在空间非相干照明物体,和多色光(如日光)照明物体的成像方面。     

Even illumination in total internal reflection fluorescence microscopy using laser light

In modern fluorescence microscopy, lasers are a widely used source of light, both for imaging in total internal reflection and epi-illumination modes. In wide-field imaging, scattering of highly coherent laser light due to imperfections in the light path typically leads to nonuniform illumination of the specimen, compromising image analysis. We report the design and construction of an objective-launch total internal reflection fluorescence microscopy system with excellent evenness of specimen illumination achieved by azimuthal rotation of the incoming illuminating laser beam. The system allows quick and precise changes of the incidence angle of the laser beam and thus can also be used in an epifluorescence mode.     

聚光系统对显微物镜杂光测量影响的分析与实验

显微物镜通常采用部分相干照明,测量它的杂光时,有必要研究照明系统的影响。实验表明,对于中、低倍物镜来说,当照明系统的数值孔径变化时,物面相干性变化对显微物镜杂光测量的影响可以忽略,从而可以采用积分球面扩展光源去测量它们的杂光系数。文中对相关的问题进行了分析讨论。     

在线图像可视铁谱成像系统的像面照度均匀性

为了定量评价在线图像可视铁谱(OLVF)成像系统的像面照度均匀性,建立了一种像面照度模型。以像方参数及放大倍率表征物方视场,将物方视场区域离散化,采用朗伯余弦理论建立入瞳模式的像面照度模型,实现了像面照度的计算与均匀性评价。利用Matlab进行了物面照度仿真分析,确定了OLVF成像系统环形阵列光源的发光二极管(LED)数量,基于像面照度分析确定了最佳成像焦距和放大倍率。计算了油腔通油情况下成像系统中的光能量损耗以及磨粒沉积面的照度分布,建立了油液吸光系数与CCD像面轴上像点照度的关系。结果显示:LED发光强度已知时,仿真计算的像面不均匀度约为5.60%,实际测试的像面不均匀度为8%~9%,满足不均匀度≤10%的要求。开展了磨粒铁谱图像采集实验,结果表明:图像中磨粒清晰可辨,便于图像分割与视觉特征提取。提出的模型可定量描述OLVF成像系统的像面照度,可作为优化系统结构,提高系统成像性能的依据。     

激光主动成像图像的多帧后处理算法研究

在确定激光器的发散角度、脉冲峰值功率、接收光学系统的参数以及确定激光器和接收光学系统的几何配置后,激光主动成像系统要想得到更远距离更高分辨率的微弱目标的图像,就只受微弱目标的探测成像及处理技术的制约,因为在较长的距离和有限的激光能量下,不可能立刻照明整个目标场景,接收成像端CCD上每个像素接收到的光照度也不可能达到相当的水平。为了在特定的脉冲激光能量下增加成像系统的成像距离,同时减轻大气扰动对成像分辨率的影响,研究了一种独特的图像处理算法,用激光多脉冲来获取整个目标场景的图像,采用辐射量来确定每次曝光时间内最大景物照明区域,这种独特的多帧后处理算法,可以在大气扰动和连续散粒噪声影响下,得到比传统连续照明方式更高分辨率的图像。     

Reconstructing complex 3D objects by a Structured illumination methods

The problem of creating exact 3D models of complex real objects for virtual reality applications is considered. One of the systems reconstructing 3D coordinates of a scene from its 2D image by means of structured illumination is presented. Problems related with system operation and leading to reconstruction errors are described. A new method is proposed for improving performance of the system due to considering optical distortions and using several images for reconstructing the same scene area.     

一种基于图像拼接技术的微操作系统

针对微操作系统中显微镜视野与分辨率之间的矛盾,将图像拼接技术应用于微操作系统中,对适用于微操作系统的图像拼接     

Optical diagnostics of mercury jet for an intense proton target

An optical diagnostic system is designed and constructed for imaging a free mercury jet interacting with a high intensity proton beam in a pulsed high-field solenoid magnet. The optical imaging system employs a backilluminated, laser shadow photography technique. Object illumination and image capture are transmitted through radiation-hard multimode optical fibers and flexible coherent imaging fibers. A retroreflected illumination design allows the entire passive imaging system to fit inside the bore of the solenoid magnet. A sequence of synchronized short laser light pulses are used to freeze the transient events, and the images are recorded by several high speed charge coupled devices. Quantitative and qualitative data analysis using image processing based on probability approach is described. The characteristics of free mercury jet as a high power target for beam-jet interaction at various levels of the magnetic induction field is reported in this paper.     

Simulation of partially coherent image formation in a compact soft X-ray microscope

In this paper, we describe a numerical method of simulating two-dimensional images in a compact soft X-ray microscope using partially coherent illumination considerations. The work was motivated by recent test object images obtained by the latest generation in-house compact soft X-ray microscope, which showed diffraction-like artifacts not observed previously. The numerical model approximates the condenser zone plate as a secondary incoherent source represented by individually coherent but mutually incoherent source points, each giving rise to a separate image. A final image is obtained by adding up all the individual source point contributions. The results are compared with the microscope images and show qualitative agreement, indicating that the observed effects are caused by partially coherent illumination.     

Köhler illumination in the TEM: Fundamentals and advantages

Köhler illumination is the most favourable design for the illumination path of an electron microscope with a condenser objective lens. The new illumination system of the EM 910 and EM 912 OMEGA allows both wide area (Köhler) illumination for TEM operation and spot illumination for analytical investigations. Compared to conventional systems and objective lenses with a condenser mini lens, this system offers many advantages. In addition to the homogeneous, highly coherent and parallel illumination of every point in the specimen, it offers advantages for selected area diffraction and spot scan mode. Combined with the electron optical selection of a condenser aperture, this illumination system provides the flexibility necessary to achieve optimum illumination for the specimen.     

Quantitative phase-amplitude microscopy I: optical microscopy

In this paper, the application of a new optical microscopy method (quantitative phase‐amplitude microscopy) to biological imaging is explored, and the issue of resolution and image quality is examined. The paper begins by presenting a theoretical analysis of the method using the optical transfer function formalism of Streibl (1985 ). The effect of coherence on the formation of the phase image is explored, and it is shown that the resolution of the method is not compromised over that of a conventional bright‐field image. It is shown that the signal‐to‐noise ratio of the phase recovery, however, does depend on the degree of coherence in the illumination. Streibl (1985) notes that partially coherent image formation is a non‐linear process because of the intermingling of amplitude and phase information. The work presented here shows that the quantitative phase‐amplitude microscopy method acts to linearize the image formation process, and that the phase and amplitude information is properly described using a transfer function analysis. The theoretical conclusions are tested experimentally using an optical microscope and the theoretical deductions are confirmed. Samples for microscopy influence both the phase and amplitude of the light wave and it is demonstrated that the new phase recovery method can separate the amplitude and phase information, something not possible using traditional phase microscopy. In the case of a coherent wave, knowledge of the phase and amplitude constitutes complete information that can be used to emulate other forms of microscopy. This capacity is demonstrated by recovering the phase of a sample and using the data to emulate a differential interference contrast image.