The Nonaberrational Width of the Angular Spectrum of a Field Probing a Layered Object in Confocal Microscopy

Optics and Spectroscopy - The influence of the numerical aperture of a light beam that probes a layered object on the magnitude of the quantity measured with a confocal interference microscope upon...     

Effect of Wavefront Properties on Numerical Aperture of Fresnel Hologram in Incoherent Holographic Microscopy

Fresnel incoherent correlation holographic （FINCH） microscopy is a recently developed new technique, which employs a spatial light modulator （SLM） as the beam splitter. Light originating from the same object point is split into two beams by the wavefront-division phase mask displayed on SLM, and a Fresnel-zone plate-like hologram is formed by the interference of the two beams. The numerical aperture NAH of the recorded Fresnel hologram is introduced as a comprehensive parameter for evaluating the imaging characteristics in the FINCH scheme. The effect of wavefront properties on NAH of the hologram is investigated theoretically in the sense of optimizing imaging resolution. The variation trends of NAH are described and an optimal NAH is achieved by implementing an appropriate phase mask for a given recording distance between SLM and CCD; thus optimized imaging resolution and signal-to-noise ratio are demonstrated experimentally.     

荧光谱线分布对共焦荧光显微镜分辨率的影响

研究了荧光谱线分布对共焦荧光显微镜中分辨率的影响,导出了荧光谱线分布的荧光功率传输函数、三维脉冲响应函数.数值计算了荧光谱线均匀分布的情况,结果表明：与采用单一中心荧光波长的分辨率比较,共焦荧光显微镜的横向分辨率、纵向分辨率随着荧光谱线范围和色散的增大而下降;谱线响应范围小的探测器有利于分辨率.     

The Effect of the Limited Aperture of an Emitter on the Width and Divergence Angle of a Laser Beam

Optics and Spectroscopy - The conditions necessary for the correct measurement of the width and divergence angle of a laser beam have been determined with consideration for the finite dimensions of...     

Erratum to: Determination of the Electrical Resistivity of Vertically Aligned Carbon Nanotubes by Scanning Probe Microscopy

Technical Physics - An Erratum to this paper has been published: https://doi.org/10.1134/S1063784221080193     

锥形光纤两端直径比与数值孔径的关系

锥形光纤不仅能传光,而且在传光过程中能将光束口径缩小或扩大。但由于锥度的影响,锥形光纤的集光能力低于普通圆柱形光纤。本文利用棱镜展开原理研究了锥度与集光能力间的关系,得出了对设计或选用锥形光纤有指导意义的结论。     

On the Possibility of Holographic Recording in the Absence of Coherence between a Reference Beam and a Beam Scattered by an Object

JETP Letters - For the holographic recording of the wave field of an object, a pattern created by the interference of the reference wave and the wave scattered by the object is used. Traditional...     

Beam Displacement in a Layered Configuration due to Formation of Standing Waves

We obtain a large positive lateral shift of a light beam reflected from a layered configuration due to the formation of the unusual standing wave, which acts like the forward surface wave. An explicitly analytic condition to obtain the large lateral shift is presented. Finally we present a numerical simulation for the lateral displacement of a Gaussian beam.     

Compensation for the Influence of Fluctuations in the Distance to the Object During Noncontact Probing in Spectral Domain Optical Coherence Tomography

Radiophysics and Quantum Electronics - We propose and experimentally test a numerical method for correction of the influence of fluctuations in the distance to objects during noncontact probing in...     

Fast Analysis for the Focusing of a Laser Beam with Amplitude Modulation and Phase Fluctuation Through an Aperture Lens

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Fast Analysis for the Focusing of a Laser Beam with Amplitude Modulation and Phase Fluctuation Through an Aperture Lens

Based on the treatment that a rectangular function can be expanded into an approximate sum of complex Gaussian functions with finite numbers, the analytical expression for the focusing intensity distribution of a laser beam with amplitude modulation (AM) and phase fluctuation (PF) through an aperture lens is derived. The typical numerical examples are given and compared with those obtained from numerically integral calculation. The results show that our method can significantly improve the numerical calculation efficiency.     

Determination of Mean Thickness of an Oxide Layer on a Silicon Sphere by Spectroscopic Ellipsometry

One of the biggest obstacles to reduce the uncertainty of the Avogadro constant NA is such that there will be an oxide layers on the surface of a silicon sphere. The thickness of this layer is measured by a modified spectroscopic ellipsometer, which can eliminate the influence of the curved surface, and the results are calibrated by x-ray reflectivity. Fifty positions distributed nearly uniformly on the surface of the silicon sphere are measured twice. The results show that the mean thickness of the overall oxide layer is 3.75 nm with the standard uncertainty of 0.21 nm, which means that the relative uncertainty component of NA owing to this layer can be reduced to 1.2 × 10^-8.     

Spectral Intensity Distribution of a Time Dependent Gaussian Pulsed Beam From a Circular Aperture in the Near-Field Diffraction

The diffraction characteristics of a broadband light source from a circular aperture in the near-field are clarified theoretically via prompt and precise mathematical derivation. This paper provides a explicit way of treating in the case of time dependent Gaussian-shaped pulsed beam passing through a circular aperture and gives more accurate and concrete criteria for judging the timing of the spectral red shift, blue shift and splitting of light distributions. Furthermore, the results offer an understanding of the Gaussian beam quality of the output of an optical resonator in the near-field.     

瞬态电磁场对多孔洞目标耦合规律的数值研究

 运用时域有限差分（FDTD）方法,用数值方法研究了瞬态电磁场对开有多个孔洞的长方体的耦合规律。分别分析了不同极化方向、不同入射方向及不同带宽的瞬态电磁场的耦合效应。入射波极化方向与孔洞的短边平行时耦合入腔体的能量最多;相同振幅、不同上升前沿和带宽的入射波以窄带、快前沿耦合入的能量为多;多孔洞腔体内场衰减很快。     

Influence of Time-of-Flight Chromatic Aberration on the Dynamics of Propagation of Pulsed Electron Beam in Ultrafast Electron Microscopy: A New Strategy for Better Temporal Resolution

Journal of Experimental and Theoretical Physics - A common strategy aimed at achieving a high temporal resolution in ultrafast electron microscopy and diffraction is based on the use of strong...     

SiO2厚度对类阴极射线发光中电子加速的影响

研究了有机 /无机复合结构ITO/SiO2 /MEH PPV/SiO2 /Al器件的类阴极射线发光性质 ,电子经过SiO2层加速后 ,激发MEH PPV层发光。发光除了MEH PPV激子发光峰外 ,还有一个带间复合的能量更高的短波发光峰。通过 2个发光峰随SiO2 层的厚度的变化规律 ,研究了SiO2 对电子的加速能力。