共查询到20条相似文献,搜索用时 143 毫秒
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《北京大学物理学丛书》第一辑中的《近代光学信息处理》一书与我们见面了.作者以简捷的笔法论述了光学信息处理的各个分支以及相关领域的基本理论及其重要的应用.书中概览了光学信息处理前沿领域的重要研究成果和本学科近期发展动向.作者的论述简明严谨、自成体系,也包括了他们自己多年来在该领域中的科学研究成果、学术贡献和独到的见解.信息光学是近代光学的一个重要的主题,而信息光学的精髓便是“近代光学信息处理”.近代光学信息处理的基础是傅里叶光学.书中的第一章非常简要地阐述了傅里叶光学基础,从二维傅里叶分析的扼要叙… 相似文献
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在考虑随机因素的情况下, 应用蒙特卡罗方法在理论上详细研究了锶原子束二维激光准直的动力学过程. 综合考虑原子横向发散角、初始原子位置、纵向速度分布、同位素等因素, 获得了激光二维准直后的原子横向空间分布的模拟结果以及随准直光失谐、光功率等参量因素的变化. 通过与实验数据比较, 理论值和实验值很好相符, 显示蒙特卡罗方法可以精确地描述锶原子束二维准直的动力学过程. 为原子束激光二维准直的精确控制, 高精度原子钟系统的优化, 提供了一种理论分析方法.
关键词:
二维准直
蒙特卡罗方法
横向空间分布 相似文献
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角度准直器在高能质子照相中有着重要作用,既可以利用准直器提高图像对比度,又能通过二次成像实现材料诊断及密度重建,因此减小通过准直器后通量值的误差具有重要意义.本文通过理论分析,提出了一种高能质子照相中准直器设计的方法,通过Geant4程序建立了1.6 GeV的质子成像系统,该系统分别使用理想准直器、拉伸型准直器和利用该方法设计的准直器,并对比通过客体后的通量分布.结果表明,在使用理想准直器和该方法设计的角度准直器时,二者得到的客体的通量分布符合较好,而使用拉伸型准直器时,与使用理想准直器得到的结果相差较大.因此利用理想准直器方法设计的准直器可以很好地减小通量误差. 相似文献
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一、引言自从1960年激光器问世后,人们获得了新的相干光源,从而得以更有效地将通信理论应用于光学系统的分析与综合,并逐渐形成了一个新的光学分支,叫作傅里叶光学。目前,傅里叶光学的概念与方法已在很多工程与科学领域得到日益广泛的应用。在傅里叶光学中,为了分析与综合各种光学系统,就要对诸光学元件或一个光学系统的诸部分进行计算。这就需经常计算菲涅耳-基尔霍夫衍射积分。如果系统所包含的元件较多,或者要处理起不同作用的几个系统的级联时,计算这些积分就相当麻烦,从而给分析与 相似文献
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计算全息检测非球面干涉场的理论分析与实验结果 总被引:2,自引:0,他引:2
本文应用光学全息术及傅里叶光学的理论对计算全息图干涉检测非球面面形的光路及干涉场进行了理论分析,提出了其干涉场为不定域干涉的观点,并在实验中予以证实. 相似文献
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二维傅里叶变换光谱是近几十年来发展起来的一种先进光谱技术. 与其他超快光谱方法相比,它具有许多优点,并且为研究各种复杂系统提供了巨大的机会. 然而,二维傅里叶变换光谱的系统搭建、实验测量和理论描述仍面临许多挑战,从而限制了其广泛应用. 近年来,随着超快激光等各种相关技术的发展和革新,二维傅里叶变换光谱方法也逐渐发展成熟,进而大大降低了进行二维傅里叶变换光谱实验的技术壁垒. 对于二维傅里叶变换光谱实验装置的光学设计,目前存在许多不同的方法,每种方法都有其自身的优点和局限性. 但是目前还没有一个简单的教程可以帮助实验工作者选择搭建其第一套二维傅里叶变换光谱实验装置. 因此,本文旨在为计划搭建其第一套二维傅里叶变换光谱实验装置的初学者提供一个简短的介绍. 相似文献
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We find that the Collins diffraction formula in cylindrical coordinates is just the transformation matrix element of a three-parameter two-mode squeezing operator in the deduced entangled state representation. This is a new tie connecting the unitary transform in quantum optics to the generalized Hankel transform in Fourier optics. The group multiplication rule of the squeezing operators maps to the Collins formula related to two successive Hankel transforms. 相似文献
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《Infrared physics》1990,30(2):155-159
An analytic model is presented for the spectral degradation introduced into Fourier transform spectroscopy by the presence of imperfect figure in the optics of a two beam interferometer. It allows tolerances to be defined for the figure of the optics if a required level of spectral performance is to be achieved. It confirms the validity of the practical rule-of-thumb that optical figures true to within a tenth of the shortest wavelength of interest will not degrade performance unacceptably. 相似文献
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The interest in transient analysis of acoustic waves has been growing in recent years, due to the advance of wide-band sonars. In this paper, a transient analysis method for acoustic backscattering signals is proposed based on the time domain physical optics (TDPO). TDPO is formulated via a theoretical inverse Fourier transform of the conventional physical optics formula used in the frequency domain wave scattering analyses. A hidden surface removal algorithm using an adaptive triangular beam method and a virtual surface concept are adopted to explain shadow effects and multiple reflections among elements, respectively. Numerical analyses are carried out for two kinds of underwater targets: a submarine pressure hull and an idealized submarine, in order to validate the proposed method. The result of the submarine pressure hull shows good agreements between the proposed method and conventional physical optics based on inverse fast Fourier transform. Additionally, the result of the idealized submarine shows that the proposed method is efficient for finding highlights including their contribution to the whole backscattering signal. 相似文献
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Weiwei Huang 《Optics Communications》2008,281(18):4577-4580
The analyses of the imaging performance of the wavefront coding system are always based on the Fourier optics. In this paper, geometrical optics is used to analyze the imaging characteristics of arbitrary phase mask in the wavefront coding system. The characteristics of the spot diagrams created by odd and even symmetrical phase masks, including the size, upper and lower boundaries, ray structure, and the stability, are analyzed by the ray aberration theory. These characteristics are also compared with those obtained by Fourier optics, and the two sets of characteristics are proved to be consistent with each other quite well. 相似文献
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Valeriy Titarenko 《Journal of synchrotron radiation》2016,23(6):1447-1461
Ring artefacts are the most disturbing artefacts when reconstructed volumes are segmented. A lot of effort has already been put into better X‐ray optics, scintillators and detectors in order to minimize the appearance of these artefacts. However, additional processing is often required after standard flat‐field correction. Several methods exist to suppress artefacts. One group of methods is based on minimization of the Tikhonov functional. An analytical formula for processing of a single sinogram was developed. In this paper a similar approach is used and a formula for processing two‐dimensional projections is found. Thus suppression of ring artefacts is organized as a two‐dimensional convolution of `averaged' projections with a given filter. Several approaches are discussed in order to find elements of the filter in a faster and accurate way. Examples of experimental datasets processed by the proposed method are considered. 相似文献
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A high-resolution sensor for measuring the refractive index of liquids using a reflective arrayed-waveguide grating (AWG) is proposed. The refractive index of a liquid placed in the groove of the arrayed region is measured via the shift of the maximum intensity in the imaging plane of the AWG owing to the phase change in the region. The refractive index can be monitored in real time by measuring the power ratio between two output waveguides of the AWG with a narrow-band source. A mathematical model based on Fourier optics and wave optics is established. A fitting formula for the relationship between the power ratio and the refractive index of liquid is derived. The results of the study show that the proposed method can eliminate the effects of instability of the light source and the inner loss of the system and provide a refractive index resolution of 10−7. 相似文献
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Using squeezing transform in the context of quantum optics and based on the Fourier series expansion we rigorously derive a new Poisson sum formula. Application of this new formula to the representation transformation of kq-wave function for describing electrons in periodic lattice is demonstrated. In so doing, the transition matrix element of harmonic oscillator in kq representation is derived. 相似文献
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Lin Dong Sergei Popov Sergey Sergeyev Ari T. Friberg 《Central European Journal of Physics》2010,8(2):228-234
An improved approach for narrow-band wavelength selection in tunable lasers is described. To provide the tunability, a reconfigurable
diffractive optical element (DOE) based on a programmable spatial light modulator (PSLM) is applied. With a proper choice
of the phase transfer function of the PSLM, the device can be used as a dispersive intra-cavity component for precise tuning
within the lasing spectral band of a solid-state dye laser. The suggested design allows avoiding the mechanical movement of
any cavity components. The tunability performance and simulation are demonstrated using the Fourier optics method. 相似文献
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Eccentric photorefraction usually is used as early eyesight diagnostic test of infants and small children. Unlike currently approved geometrical optical model of eccentric photorefractometer, the crescent formation and the light-intensity distribution in the pupil image of a myopic eye are analyzed by Fourier optics with the assumption of an isotropic scattering retina. In the case of little circular light source and rectangular slit, the simulation results of different myopic diopters are obtained by geometrical optical theory and Fourier optics respectively. It is found that the simulation results by Fourier optics are similar as those obtained by geometrical optics, and all simulations are almost corresponding to the experimental result.The result demonstrates that the new method presented here is feasible. 相似文献