检索结果-内蒙古大学图书馆

optical transfer functions of 4Pi confocal microscopes: Theory and experiment

OPTICS LETTERS 1997年第7期22卷 436-438页

作者： Schrader, M Kozubek, M Hell, SW Wilson, T Department of Engineering Science University of Oxford Parks Road Oxford OX1 3PJ UK

We measure the point-spread function in the two main configurations of 4Pi confocal microscopy as well as in the traditional confocal arrangement and derive the optical transfer functions from the experimental data. The optical transfer functions are in good agreement with their theoretical counterparts. We find a 3.5- to 5-fold increased axial bandwidth of the 4Pi confocal microscope and hence confirm the enhanced spatial-frequency content of 4Pi images. (C) 1997 optical Society of America.

关键词： Confocal microscopy Constructive interference Imaging systems optical transfer functions Point spread function Spatial frequency

来源：评论

学校读者我要写书评

暂无评论

Nonstationary optical transfer functions of underwater imaging systems

引用

APPLIED OPTICS 2017年第27期56卷 7518-7524页

作者： Luchinin, Alexander G. Kirillin, Mikhail Yu. Russian Acad Sci Inst Appl Phys 46 Ulyanov St Nizhnii Novgorod 603950 Russia

optical transfer functions of underwater imaging systems employing narrow pulses or sinusoidally modulated beams for image formation are studied. A modified Monte Carlo technique allowing for direct statistical modeling of these functions accounting for temporal dispersion is proposed and implemented. The optical transfer functions are calculated for various modulation frequencies of the illumination beam and for the case of pulsed illumination. The employment of high-frequency sinusoidal or pulsed modulation with consistent processing of the received signal is shown to significantly increase the contrast sensitivity of underwater imaging systems as compared with systems with stationary illumination. (C) 2017 optical Society of America

关键词： Image processing Image quality Imaging systems optical transfer functions Underwater imaging Visual contrast sensitivity

来源：评论

学校读者我要写书评

暂无评论

optical incoherent synthetic aperture imaging by superposition of phase-shifted optical transfer functions

引用

OPTICS LETTERS 2021年第7期46卷 1712-1715页

作者： Rai, Mani Ratnam Rosen, Joseph Ben Gurion Univ Negev Sch Elect & Comp Engn POB 653 IL-8410501 Beer Sheva Israel

The concept of an optical incoherent synthetic aperture is widely used in astronomical interferometric telescopes. In this Letter, we propose a new, to the best of our knowledge, method to realize optical incoherent synthetic aperture imaging. The method is based on a superposition of optical transfer functions of incoherent imaging systems. Only two small sub-apertures, out of a much larger full synthetic aperture, are open at any given time, and they transfer light from the observed object to the image sensor. During the imaging process, the two sub-apertures move over the full synthetic aperture, where the gap between them starts from zero and grows with time. For every position of the pair of sub-apertures, two images are captured. In one of the images, the sub-apertures have the same phase value, and in the other image, one of the sub-apertures is phase shifted by pi radian relative to the other one. The final image with the image resolution of the synthetic aperture is obtained as a superposition of the entire recorded images. optical experiments are performed on reflective objects, and results of the synthetic aperture-based method demonstrate an imaging performance similar to that of direct imaging by a system with a single aperture of the size of the synthetic aperture. (C) 2021 optical Society of America

关键词： Aperture synthesis Astronomical telescopes Image processing Imaging systems optical transfer functions Synthetic aperture imaging

来源：评论

学校读者我要写书评

暂无评论

INFLUENCE OF NOISE ON MEASUREMENT OF optical transfer-functions BY DIGITAL FOURIER-TRANSFORM METHOD

引用

JOURNAL OF THE optical SOCIETY OF AMERICA 1975年第5期65卷 502-508页

作者： TAKEDA, M OSE, T UNIV TOKYO INST IND SCI7-22-1 ROPPONGIMINATO 106TOKYOJAPAN

A general formula for the expected value of the error in the measured optical transfer function due to noise has been derived from a matrix expression of the digital Fourier-transform process and introducing an error matrix. A new method of OTF measurement, using a multiple slit, is proposed and compared with the conventional single-slit and knife-edge scanning methods. The relation between the expected value of the error in the optical transfer function and that in the modulation transfer function is studied theoretically. Experiments have been carried out to verify the results of the analysis.

关键词： Matrix methods Modulation transfer function optical measurement optical transfer functions Spatial frequency White light

来源：评论

学校读者我要写书评

暂无评论

optical incoherent imaging using annular synthetic aperture with the superposition of phase-shifted optical transfer functions

引用

OPTICS LETTERS 2022年第16期47卷 4012-4015页

作者： Desai, Jawahar Prabhakar Kumar, Ravi Rosen, Joseph Ben Gurion Univ Negev Sch Elect & Comp Engn POB 653 IL-8410501 Beer Sheva Israel

The optical incoherent synthetic aperture (SA) has wide applications in astronomy and biomedical optics. Super-resolution imaging can be achieved through SAs with an effective size several times larger than the size of the physical apertures. In this Letter, we propose a new, to the best of our knowledge, method to realize optical incoherent SA imaging. Instead of scanning the entire area of the full SA, we show that similar imaging performance can be achieved by scanning only along its perimeter. At any given time, only a single pair of sub-apertures located at the SA perimeter is open and reflects the incident light toward an image sensor. For each location of the two sub-apertures, two interfering images are captured. The phase difference between the two sub-apertures is zero for one interfering image and pi for the other. The image of the object is reconstructed by superposition of all the interfering images from some of the sub-aperture locations and with the two-phase differences, 0 and p, between the two sub-apertures. optical experiments have been performed using reflective objects, and the results demonstrate similar imaging capabilities as that of direct imaging with the aperture size of the SA. Furthermore, we have compared the proposed SA imaging results with the results of annular and full aperture direct imaging. (C) 2022 Optica Publishing Group

关键词： Aperture synthesis Fresnel incoherent correlation holography Image sensors Imaging techniques optical transfer functions

来源：评论

学校读者我要写书评

暂无评论

DEPENDENCE OF 2-DIMENSIONAL AND 3-DIMENSIONAL optical transfer-functions ON PINHOLE RADIUS IN A COHERENT CONFOCAL MICROSCOPE

引用

JOURNAL OF THE optical SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION 1992年第5期9卷 725-731页

作者： DRAZIC, V Institut für Mess- und Regelungstechnik Universität (Technische Hochschule) Karlsruhe Postfach 69 80 D-7500 Karlsruhe Germany

Previous papers about coherent scanning optical microscopes took into account two types of microscope: those with a point detector called type-II or confocal microscopes and those with an infinitely large area detector called type-I or conventional microscopes. Here the pinhole size of a type-II microscope was permitted to vary, and it is shown how the size could affect the imaging properties of a real microscope. The three-dimensional optical transfer function is established, and we discuss in particular the resolution capabilities, lateral as well as longitudinal, of a scanning microscope with a given pinhole size or detector area. Finally, a rigorous confocality criterion, which will answer the question of how small the pinhole should be made to give confocal imaging properties to a scanning microscope, is given.

关键词： Confocal microscopy Image processing Microscopy optical transfer functions Scanning microscopy Three dimensional imaging

来源：评论

学校读者我要写书评

暂无评论

DEPENDENCE OF 3-D optical transfer-functions ON THE PINHOLE RADIUS IN A FLUORESCENT CONFOCAL optical MICROSCOPE

引用

APPLIED OPTICS 1990年第20期29卷 3007-3011页

作者： KIMURA, S MUNAKATA, C []The authors are with Hitachi Ltd. Central Research Laboratory Kokubunji Tokyo 185 Japan.

The resolution of a fluorescent confocal scanning optical microscope (CSOM) is superior to that of a conventional fluorescent optical microscope. To attain this superiority, the fluorescent CSOM uses a pinhole in front of the detector. Thus, the resolution of the CSOM is dependent on the pinhole radius. Three-dimensional optical transfer functions are calculated for the various radii to elucidate this dependence. The results show that a CSOM with a radius smaller than ~1 optical unit has a bandwidth comparable with that of an infinitely small radius.

关键词： Fast Fourier transforms Fourier transforms optical microscopy optical transfer functions Point spread function Spatial frequency

来源：评论

学校读者我要写书评

暂无评论

INCORPORATION OF DIRECTIONAL EFFECTS OF THE RETINA INTO COMPUTATIONS OF optical transfer-functions OF HUMAN EYES

引用

JOURNAL OF THE optical SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION 1989年第12期6卷 1941-1944页

作者： ARTAL, P []Instituto de Optica Consejo Superior de Investigaciones Científicas Serrano 121 28006 Madrid Spain

Two-dimensional optical transfer functions (OTF’s) of individual human eyes are computed from the retinal images of a point test object, using a phase-retrieval method. The retinal reflection directionality effect is included in the computations by means of an apodization pupil, and subsequently the Stiles–Crawford effect is also considered. The modulation transfer functions obtained when the retinal reflection directionality effect is considered show lower values of the modulation; on the other hand, their two-dimensional form and the corresponding phase transfer functions remain practically unchanged. The importance of the Stiles–Crawford apodization depends on the wave aberration of the individual subject, but in general it produces an improvement in image quality, and the modulation transfer function becomes more symmetrical.

关键词： Image processing Image quality Modulation transfer function optical transfer functions Pupil Spatial frequency

来源：评论

学校读者我要写书评

暂无评论

SIGNIFICANCE OF PHASE OF optical transfer functions

引用

JOURNAL OF THE optical SOCIETY OF AMERICA 1968年第11期58卷 1505-&页

作者： HUFNAGEL, RE The Perkin–Elmer Corporation Norwalk Connecticut 06852

A proper assessment of image quality in terms of optical transfer functions requires that the phase angle, as well as the absolute value of the OTF be taken into account. This paper discusses one procedure for account... 详细信息

关键词： Fourier transforms Gravity Image quality Modulation transfer function optical transfer functions Point spread function

来源：评论

学校读者我要写书评

暂无评论

DEPENDENCE OF 2-DIMENSIONAL AND 3-DIMENSIONAL optical transfer-functions ON PINHOLE RADIUS IN A COHERENT CONFOCAL MICROSCOPE - REPLY

引用

JOURNAL OF THE optical SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION 1993年第3期10卷 535-537页

作者： DRAZIC, V Institut für Mess- und Regelungstechnik Universität (Technische Hochschule) Karlsruhe Postfach 69 80 D-7500 Karlsruhe 1 Germany

The aim of this reply to comments is to show how the Fourier transform in depth of the defocused two-dimensional (2D) weak-object transfer function is to be physically interpreted in a confocal microscope. The origin of discrepancies in the shape of the three-dimensional (3D) transfer function as presented by Sheppard and Gu [Opt. Commun. 81, 281 (1991)] and by the present author [J. Opt. Soc. Am. A 9, 725 (1992)] are also explained. Finally, a class of 3D objects is presented to which the 3D transfer function of my earlier paper applies.

关键词： Confocal microscopy Fourier transforms optical transfer functions Scattering Three dimensional imaging Transmission coefficient

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：