紧聚焦条件下的轴向双焦点波带片EI北大核心CSCD

基于紧聚焦条件下的矢量衍射理论推出了一个解析解形式的环半径公式,利用此公式设计得到的二元相位波带片可以使入射光的紧聚焦区域呈现轴向双焦点分布。并且,公式中的两个焦点的轴向距离和环半径直接相关,可以设计一系列的具有不同轴向距离的二元相位波带片,用来调制高数值孔径物镜,使其产生轴向可调的双焦点。以径向偏振贝塞尔-高斯光束为例,数值模拟了在不同轴向偏移距离的二元相位波带片的调制下的紧聚焦场的空间强度分布。数值模拟结果表明,基于此类二元相位波带片可以成功地实现轴向距离可调的双焦点。此外,利用一些具有特殊轴向距离的二元相位波带片,还可产生"光泡"与"光针"等特殊的紧聚焦场分布。因此,此类二元相位波带片有望应用于微粒子的动态操控与捕获。     

紧聚焦条件下的轴向双焦点波带片

基于紧聚焦条件下的矢量衍射理论推出了一个解析解形式的环半径公式,利用此公式设计得到的二元相位波带片可以使入射光的紧聚焦区域呈现轴向双焦点分布。并且,公式中的两个焦点的轴向距离和环半径直接相关,可以设计一系列的具有不同轴向距离的二元相位波带片,用来调制高数值孔径物镜,使其产生轴向可调的双焦点。以径向偏振贝塞尔-高斯光束为例,数值模拟了在不同轴向偏移距离的二元相位波带片的调制下的紧聚焦场的空间强度分布。数值模拟结果表明,基于此类二元相位波带片可以成功地实现轴向距离可调的双焦点。此外,利用一些具有特殊轴向距离的二元相位波带片,还可产生"光泡"与"光针"等特殊的紧聚焦场分布。因此,此类二元相位波带片有望应用于微粒子的动态操控与捕获。     

使用二元相位菲涅尔波带片产生轴向线聚焦

介绍了一种全新的轴向线聚焦方案.采用菲涅尔波带片，在实验中产生了沿轴向长为5mm，宽 100μm的线聚焦.光学测量表明，线聚焦轴向强度分布比较均匀.这些参数基本上可以满足激 光等离子体实验的要求. 关键词： 菲涅尔波带片 轴向线聚焦     

螺旋型波带片聚焦特性研究

提出了一种计算螺旋型波带片聚焦特性的方法。从衍射积分理论出发对螺旋型波带片的聚集特性进行了理论计算,推导出了级数形式的解析解,获得了螺旋型波带片"空心"焦点的场强分布。利用螺旋型波带片的聚焦特性,对其成像进行了数值模拟和理论分析。理论分析表明螺旋型波带片的空间分辨率与其"空心"焦点的环宽有关。通过验证实验证明理论分析与实验测试一致,为螺旋型波带片成像理论和模拟计算提供了一种有效手段。     

菲涅尔波带片对高斯光束的变换

从波带片的特性出发研究高斯光束通过波带片的聚焦特性。用失调望远系统的失调量变化调节出射光束聚焦点的位置，并对聚焦点的变化范围和光斑大小进行描述，最后对波带片对高斯光束聚焦特性进行评价。     

波带片离焦量和非单色光对光斑的影响

考虑了波带片在离焦和非单色光照明条件下的光斑特性，通过数值计算，得到了在不同离焦量时光强分布曲线、光斑大小、以及特定范围内总能量随离焦量的变化；同时得到不同带宽的光强分布曲线、光斑半径随带的变化曲线。并研究了用于软Ｘ光扫描显微镜的聚焦波带片允许的离焦误差以及光斑半径与带宽的关系。     

高斯光束经相位连续变化型波带片的衍射特性

 根据瑞利-索末菲标量衍射理论分析了相位连续变化型波带片对高斯光束的衍射特性。在高斯光束入射下,对相位连续变化型波带片光轴和焦平面上的太赫兹强度分布特性进行了模拟,分析了入射光束的束腰半径和束腰位置对衍射场的影响,并与平面波入射的情况进行了对比。数值结果显示,相位连续变化型波带片可以实现对高斯分布太赫兹波的聚焦。相位连续变化型波带片的衍射规律与薄透镜的聚焦规律相似。通过合理调整束腰与波带片之间的距离可以保证衍射效率在85%以上。与平面波相比,高斯光束入射下的焦点处中心场强较小,但衍射效率较高。     

具有准单级聚焦特性的梯形波带片（英）

为改进用于X射线聚焦的二值化Gabor波带片目前所存在的结构复杂、不利于加工制作的问题,在不改变梯形透过率函数的前提下,通过将传统的梯形孔基元变为平行四边形基元应用于波带片的设计之中,提出了一种聚焦效率更高的具有准单级聚焦特性的波带片。理论推导显示,该波带片除了像Fresnel波带片一样能够消除偶数级的焦点外,还可以消除3q级（q为整数）的焦点,1/m4（m为焦点级数）的效率衰减系数也使得高级衍射得到了很好的抑制。MATLAB数值模拟的结果证明,该波带片的特性不仅满足以上推论,还具有比Fresnel波带片和环带扇形基元阵列波带片更低的背景噪声,可以看作是一种准单级聚焦的新型波带片。此外,在同一波带内,这种基于平行四边形基元孔的波带片设计的透光区始终保持各处的径向宽度为该波带的一半,且扇区结构简单一致,能够降低不少加工难度,易于推广应用。     

软X射线相位型聚焦波带片的研制

软X射线波带片是软X射线光学中聚焦、色散和成像的重要元件。以激光全息-离子束刻蚀技术制作金的振幅型软X射线聚焦波带片,以此为掩模,利用接触式同步辐射光刻和离子束刻蚀技术在聚酰亚胺衬底上,分别制作出了镍和锗的软X射线相位型聚焦波带片。     

具有准单级聚焦特性的梯形波带片（英文）

为改进用于X射线聚焦的二值化Gabor波带片目前所存在的结构复杂、不利于加工制作的问题,在不改变梯形透过率函数的前提下,通过将传统的梯形孔基元变为平行四边形基元应用于波带片的设计之中,提出了一种聚焦效率更高的具有准单级聚焦特性的波带片。理论推导显示,该波带片除了像Fresnel波带片一样能够消除偶数级的焦点外,还可以消除3q级(q为整数)的焦点,1/m~4(m为焦点级数)的效率衰减系数也使得高级衍射得到了很好的抑制。MATLAB数值模拟的结果证明,该波带片的特性不仅满足以上推论,还具有比Fresnel波带片和环带扇形基元阵列波带片更低的背景噪声,可以看作是一种准单级聚焦的新型波带片。此外,在同一波带内,这种基于平行四边形基元孔的波带片设计的透光区始终保持各处的径向宽度为该波带的一半,且扇区结构简单一致,能够降低不少加工难度,易于推广应用。     

Diffraction and scattering of TM plane waves from a binary periodic random surface

This paper deals with the diffraction and scattering of a TM plane wave from a binary periodic random surface generated by a stationary binary sequence using the stochastic functional approach. The scattered wave is represented by a product of an exponential phase factor and a periodic stationary process. Such a periodic stationary process is regarded as a stochastic functional of the binary sequence and is expressed by an orthogonal binary functional expansion with band-limited binary kernels. Then, hierarchical equations for the binary kernels are derived from the boundary condition without approximation. We point out that binary kernels obtained by a single scattering approximation diverge unphysically when the periodic random surface is zero on average, thus the effects of multiple scattering should be taken into account. The expressions of such binary kernels are obtained using the multiply renormalizing approximation. Then, statistical properties such as differential scattering cross-section and the optical theorem are numerically calculated with the first two order binary kernels and illustrated in the figures. It is found that the incoherent Wood's anomaly appears in the angular distribution of scattering even when the surface has zero average.     

Wave scattering from a periodic random surface generated by a stationary binary sequence

This paper studies the scattering of a TE plane wave from a periodic random surface generated by a stochastic binary sequence using a stochastic functional method. The scattered wave is first expressed as a product of an exponential phase factor and a periodic stationary process. The periodic stationary process is then expressed by a harmonic series representation, that is a 'Fourier series' with 'Fourier coefficients' given by mutually correlated stationary processes. These stationary processes are regarded as stochastic functionals of the binary sequence and they are represented by orthogonal binary functional expansions with band-limited binary kernels. The binary kernels are determined up to the second order from the boundary condition. Then, several statistical properties of the scattering are calculated numerically and illustrated in figures. It is found that, in the binary case, the second-order scattering cross section has a subtractive term and becomes much smaller than the first-order one.     

Stability of Macroscopic Binary Systems

The Darwin instability effect in the binary systems(di-planets, di-stars, and di-galaxies) is analyzed within the model based on the Regge-like laws. All possible binary stars are found satisfying the Darwin instability condition that requires to search for other mechanism triggering the merger of the contact binary objects. New analytical formulas are obtained for the orbital rotation period and the relative distance between components of the binary system. The decreasing and increasing periods as functions of mass asymmetry are related, respectively, with the non-overlapping and overlapping stage of the binary object evolution.     

二元光学进展

对二元光学的产生和发展作了简要的介绍，通过说明二元学光元件的设计和制作过程，建立二元光学的基本概念，阐述了二元光学的主要应用。     

BINARY DARBOUX TRANSFORMATION AND QUASIDETERMINANT SOLUTIONS OF THE CHIRAL FIELD

The standard binary Darboux transformation is composed and is used to obtain exact multisoliton solutions of the chiral field model in two dimensions. The solutions are expressed in terms of quasideterminants. It has been shown that the standard binary Darboux transformation is equivalent to the elementary binary Darboux transformation.     

深蚀刻二元光学元件

提出一种新颖的，蚀刻位相深度超过２π的深蚀刻二元光学技术，并从理论上分析深蚀刻二元光这元件与衍射效率的关系，然后用计算机进行模拟与分析，得到深蚀刻二元光学元件特性后一些初步研究结果。     

Concentration dependence of the surface tension for binary systems

A new equation for calculating the surface tension of binary systems is derived from fundamental thermodynamic relations. The validity of the equation is verified for 16 binary systems. It is demonstrated that the results of the calculations are in good agreement with the experimental data obtained for binary systems with smooth isotherms of the surface tension.     

From Dinuclear Systems to Close Binary Stars and Galaxies

The evolution of close binary cosmic objects in the mass-asymmetry coordinate is considered. Conditions for the formation of stable symmetric binary stars and galaxies are analyzed. The role of symmetrization of an asymmetric binary system in the transformation of the potential energy into the internal energy and in the release of a large amount of energy is explained.     

蓄冷用二元气体水合物工质匹配的研究

揭示了蓄冷用二元气体水合物相对单一气体水合物在生长动力学、相平衡热力学等生长特性方面的优越性,可以缩短水合物生长进程,具有共融和非共融的相变特性。同时结合HCFCS淘汰替代的进程,以及国内外最新的蓄冷工质研究进展,根据不同蓄冷工质匹配可以实现性能优势互补的原则,列出了新型环保水合物蓄冷的工质对。最后指出了工质匹配研究中应该注意的问题,对水合物蓄冷走向实用化作了展望。     

The two-dimensional alternative binary L-J system: liquid——gas phase diagram

A two-dimensional (2D) binary system without considering the　Lennard-Jones (L-J) potential has been studied by using the　Collins model. In this paper, we introduce the L-J potential　into the 2D binary system and consider the existence of the　holes that are called the ``molecular fraction". The liquid--gas　phase diagram of the 2D alternative binary L-J system is obtained. The　results are quite analogous to the behaviour of 3D substances.