共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
Auksorius E Boruah BR Dunsby C Lanigan PM Kennedy G Neil MA French PM 《Optics letters》2008,33(2):113-115
We demonstrate stimulated emission depletion (STED) microscopy implemented in a laser scanning confocal microscope using excitation light derived from supercontinuum generation in a microstructured optical fiber. Images with resolution improvement beyond the far-field diffraction limit in both the lateral and axial directions were acquired by scanning overlapped excitation and depletion beams in two dimensions using the flying spot scanner of a commercially available laser scanning confocal microscope. The spatial properties of the depletion beam were controlled holographically using a programmable spatial light modulator, which can rapidly change between different STED imaging modes and also compensate for aberrations in the optical path. STED fluorescence lifetime imaging microscopy is demonstrated through the use of time-correlated single photon counting. 相似文献
4.
5.
The dependence of the spatial resolution and field of view of an optical microscope equipped with a CCD camera on the objective magnification has been experimentally investigated. Measurement of these characteristics has shown that a spatial resolution of 20–25 px/μm at a field of view of about 110 μm is quite realistic; this resolution is acceptable for a detailed study of the processes occurring in cell. It is proposed to expand the dynamic range of digital camera by measuring and approximating its light characteristics with subsequent plotting of the corresponding calibration curve. The biological objects of study were human adipose tissue cells, as well as erythrocytes and their immune complexes in human blood; both objects have been investigated in vitro. Application of optical digital microscopy for solving specific problems of cytology and hematology can be useful in both biomedical studies in experiments with objects of nonbiological origin. 相似文献
6.
We propose the principle of operation of an optical near-field microscope on the basis of linear steady-state optical dimensional resonances in the system atom-probe–atoms of the sample. It is shown that such a microscope has high sensitivity and a spatial resolution of less than 1 nm and does not set limits on the choice of samples. The distribution of the optical fields in the wave and near zones in the near-field microscope at frequencies close to the optical dimensional resonances arising as a result of dipole-dipole interactions of atoms at small distances has been investigated. The optical scheme of the monatomic near-field microscope is presented. 相似文献
7.
Bartosz Krajnik Tim Schulte Dawid Piątkowski Nikodem Czechowski Eckhard Hofmann Sebastian Mackowski 《Central European Journal of Physics》2011,9(2):293-299
We developed a fluorescence confocal microscope equipped with a hemispherical solid immersion lens (SIL) and apply it to study
the optical properties of light-harvesting complexes. We demonstrate that the collection efficiency of the SIL-equipped microscope
is significantly improved, as is the spatial resolution, which reaches 600 nm. This experimental setup is suitable for detailed
studies of physical phenomena in hybrid nanostructures. In particular, we compare the results of fluorescence intensity measurements
for a light-harvesting peridinin-chlorophyll-protein (PCP) complex with and without the SIL. 相似文献
8.
9.
We present a new optical microscope in which the light transmitted by a sample-scanned transmission confocal microscope is frequency-tripled by SiOx nanocrystallites in lieu of being transmitted by a confocal pinhole. This imaging technique offers an increased contrast and a high scattered light rejection. It is demonstrated that the contrast close to the Sparrow resolution limit is enhanced and the sectioning power are increased with respect to the linear confocal detection mode. An experimental implementation is presented and compared with the conventional linear confocal mode. 相似文献
10.
差动共焦式纳米级光聚焦探测系统的研究 总被引:5,自引:0,他引:5
为解决纳米级大范围的非接触测量问题 ,提出了基于差动式共焦显微技术的光聚焦探测系统。介绍了系统的工作原理和结构装置 ,对系统中的关键技术进行了优化设计 ,通过对共焦光路的差动设计 ,可以有效地抑制光源的噪声和漂移对测量结果的影响。初步实验结果表明 ,该系统的轴向分辨率可达 2 nm 相似文献
11.
We show the feasibility of imaging objects having different optical scattering coefficients relative to the surrounding scattering medium using ultrasound-modulated optical tomography (UOT). While the spatial resolution depends on ultrasound parameters, the image contrast depends on the difference in scattering coefficient between the object and the surrounding medium. Experimental measurements obtained with a CCD-based speckle contrast detection scheme are in agreement with Monte Carlo simulations and analytical calculations. This study complements previous UOT experiments that demonstrated optical absorption contrast. 相似文献
12.
The first demonstration, to the best of our knowledge, of electro-optical microscopy is presented and applied to a polymer-based optical device. A confocal transmission microscope with interferometric homodyne detection is implemented to measure Pockels phase shifts with micrometric spatial resolution and an accuracy level down to 4 x 10(-7) rad. This technique is applied to poled polymer films in which noncentrosymmetric molecular orientation is preliminarily achieved in the sample plane between transverse planar electrodes. The electro-optic mapping of this structure exhibits nonuniform and asymmetric patterns of the nonlinear response that are characteristic of the poling spatial inhomogeneity as confirmed by second-harmonic generation microscopy. 相似文献
13.
空间低频光共焦扫描法透过散射介质成象 总被引:3,自引:0,他引:3
本文使用4-F光学系统实现低通空间频率滤波,采用空间低频光共焦扫描法透过散射介质成象,实验表明,光路中加入简单的空间滤波系统后,明显改善共焦扫描法的成象质量和分辨率。 相似文献
14.
随着现代科技对纳米微观区域兴趣的增加,如DNA测序、分子纳米器件微结构检测等,其对拉曼光谱技术的空间分辨力提出了更高的要求,而现有共焦拉曼光谱技术受自身原理限制,空间分辨力已无法满足科学需求。针对这一问题,在现有共焦拉曼光谱技术的基础上,提出一种基于最大似然算法的共焦拉曼光谱成像方法。该方法将超分辨图像复原技术与共焦拉曼光谱技术相结合,利用基于Poisson-Markov约束的最大似然超分辨复原算法对共焦拉曼光谱图像进行超分辨图像复原处理,恢复图像高频成分,进而改善共焦拉曼光谱系统的空间分辨能力,实现超分辨成像。仿真分析和实验结果表明,提出的基于最大似然算法的共焦拉曼光谱成像方法在不改变现有共焦拉曼光谱系统光学结构的前提下,仅对单幅拉曼光谱图像进行超分辨图像复原处理,即可将系统空间分辨力提高到200 nm,实现超分辨成像,同时该方法具有较强的噪声抑制能力。该方法有效地提高了共焦拉曼光谱系统的空间分辨力,为物理化学、材料科学等前沿领域中的高空间分辨微区光谱探测提供了一种新的途径,是一种行之有效的高空间分辨的共焦拉曼光谱成像方法。 相似文献
15.
We report a new configuration of a reflection-type confocal scanning optical microscope system for measuring the refractive index profile of an optical waveguide. Several improvements on the earlier design are proposed; a light emitting diode at 650 nm wavelength instead of a laser diode or He-Ne laser is used as a light source for better index precision, and a simple longitudinal linear scanning and a curve fitting techniques are adapted instead of a servo control for maintaining an optical confocal arrangement. We have obtained spatial resolution of 800 nm and an index precision of 2 × 10−4. To verify the system’s capability, the refractive index profiles of a conventional multimode fiber and a home-made four-mode fiber were examined with our proposed measurement method. 相似文献
16.
在研制用于对厚的生物样品进行光学断层成像的共焦扫描荧光显微镜时,由于成像信号十分微弱及存在很强的多次散射作用,因此杂散光的抑制非常重要,而信噪比、信号背景比就成为决定能否获得高对比度、高分率图像的关键。运用光学信息量的概念,在已有的光学成像系统信息量计算、共焦扫描荧光显微镜信噪比及传递函数计算的基础上,详细分析了共焦扫描荧光显微镜信息量与信噪比等之间的定量关系。该关系表明,为了充分利用共焦扫描荧光显微镜的成像性能,必须选择适当的探测小孔。所得的结果对于共焦扫描荧光显微成像系统的研制有重要的实用价值。 相似文献
17.
18.
Confocal optical microscopes offer unparalleled high sensitivity and three-dimensional (3D) imaging capability but require slow point-by-point scanning; they are inefficient for imaging moving objects. We propose a more efficient solution. Instead of indiscriminate scanning, we let the focus of the microscope pursue the object of interest such that no time is wasted on uninformative background, allowing us to visualize 3D trajectories of fluorescent nanoparticles in solution with millisecond temporal and ~200 nm spatial resolution. 相似文献
19.
A three-dimensional (3D) resolution measure for the conventional optical microscope is introduced which overcomes the drawbacks of the classical 3D (axial) resolution limit. Formulated within the context of a parameter estimation problem and based on the Cramer-Rao lower bound, this 3D resolution measure indicates the accuracy with which a given distance between two objects in 3D space can be determined from the acquired image. It predicts that, given enough photons from the objects of interest, arbitrarily small distances of separation can be estimated with prespecified accuracy. Using simulated images of point source pairs, we show that the maximum likelihood estimator is capable of attaining the accuracy predicted by the resolution measure. We also demonstrate how different factors, such as extraneous noise sources and the spatial orientation of the imaged object pair, can affect the accuracy with which a given distance of separation can be determined. 相似文献
20.
提出了直接针对惯性约束聚变(ICF)诊断目标的X射线Kirkpatrick-Baez型显微镜的像差校正和光学设计方法。在校正掠入射细光束像散的基础上,推导了内爆压缩区全视场范围内的垂轴像差表达式,进而构建了系统的空间分辨率预测模型。基于对空间分辨率和集光立体角两个关键指标的分析,结合ICF的实验要求,得到了系统的初始结构参数确定原则和光学设计流程。实例表明,该方法克服了传统的轴上球差评价的不足,设计结果能够同时满足内爆压缩区的视场、分辨率和集光效率的要求。 相似文献