用于高数值孔径物镜的可调光瞳滤波器

根据矢量衍射理论，提出了一种用于提高高数值孔径显微物镜纵向分辨率的可调二元环形光瞳滤波器，通过改变滤波器的环半径获得不同的纵向分辨率，并利用共焦显微术点扩散函数的乘积性大大地降低了旁瓣相对主瓣的比值。模拟结果表明，这种新型滤波器不仅可以提高高数值孔径物镜的纵向分辨率，同时基本上不影响横向分辨率。     

大视场投影光刻物镜的畸变特性检测

畸变特性是光刻物镜的关键指标,目前少有报道,提出了一种大视场投影光刻物镜畸变测量原理,测量系统和测量数据的处理方法. 利用该装置对研制的口径6英寸,分辨率3 μm的物镜进行了测量,得出该物镜在全视场的畸变值小于2.0 μm.     

基于OSLO的无限远像距消色差显微物镜的设计

共焦激光扫描显微镜对物镜有高分辨率、易于实现纵向扫描的要求,为此设计了高分辨率6片式无限远像距显微物镜.它的前置物镜与辅助物镜之间具有一段平行光路,因此容易实现轴向扫描.根据使用要求总体计算该物镜的外形尺寸,以像差理论为基础选择6片式的消色差物镜初始结构,用专业光学设计软件OSLO对物镜和辅助物镜进行设计和像质分析.设计结果显示,独特的6片式结构的20×物镜分辨率达到了800 lp/mm,符合共焦显微镜的使用要求.     

高分辨率大视场DTI-CCD成像物镜的设计与实现

现代光学系统中,以CCD图像传感器为探测器的图像采集子系统主要由成像物镜和CCD器件组成。成像物镜的光学特性决定了整个系统的使用性能,成像物镜的分辨率应与CCD图像传感器的像素尺寸相适配。通过运用双远心系统,并使用OSLO软件进行结构设计,实现了对高分辨率大视场DTI-CCD成像物镜的成功设计。     

波前编码显微物镜景深扩展的研究

为了解决传统显微物镜景深与分辨率的矛盾,采用波前编码的方法,设计研究了波前编码的10倍显微物镜,结合传统光学设计软件,采用基于MTF一致性的相位板参数的优化方法,实现了在像面附近一定范围内系统的点扩散函数一致性;此外,还设计了扩展三次相位编码板的10倍显微物镜,比较了采用两种不同相位板系统的焦深扩展的效果,结果显示三次相位板的焦深扩展效果较好,可以将传统10倍显微物镜的焦深扩展15倍。成像模拟仿真结果显示滤波后的编码像在±15倍焦深范围内成像清晰,从而扩大了系统的景深。     

像质补偿在高分辨物镜精密装调中的应用

根据高分辨物镜各个光学元件的实测数据,应用轴向补偿和旋转补偿法,在仿真精密装调过程中得到了物镜轴向补偿器的最优值和各元件的最佳旋转角度。仿真结果表明,在97.7%的置信区间内,物镜各视场波像差RMS值从补偿前的0.087λ(λ=632.8nm)减小到了补偿后的0.040λ。依据获得的参数对物镜进行了装调实验,结果表明,激光干涉仪测得的物镜各视场波像差RMS值介于0.050~0.082λ之间,基本达到了衍射极限的分辨率要求,验证了像质补偿方法的有效性。     

用于数字光刻的非对称式投影物镜设计

针对DMD数字光刻,利用ZEMAX光学设计软件,设计出了一套适用于型号 0.7XGA DMD的10片式光刻投影物镜。该物镜采用非对称性结构,前组为改进的三分离物镜,后组为匹兹伐物镜加平像场镜,分辨率为2 m,近轴放大倍率为-0.15,像方数值孔径NA为0.158,全视场波像差小于/20 ,畸变小于0.014%,焦深为20 m,通过各项评价可知系统已经达到了衍射极限。在对该镜头进行公差分析后,利用Monte Carlo方法,模拟组装加工了100组镜头,得到90%的镜头MTF＞0.46,50%的镜头MTF＞0.51,证明了这种非对称性结构加工和校装的可能性。     

折反式微光夜视物镜的光学设计

介绍一种长焦距、大相对孔径微光夜视物镜的光学设计。设计参数为焦距100 mm,相对孔径1/1.4,视场10。为增大视距,减小物镜尺寸和质量,并且满足在宽光谱范围消色差的要求,选择均为球面的折反式物镜结构,在相同焦距和相对孔径的条件下折反式系统比折射系统尺寸更小,质量更轻。在设计过程中引入曼金反射镜,增加设计自由度。经优化设计达到较好的成像质量,空间频率在50 lp/mm时,轴上传递函数大于0.4,轴外传递函数大于0.2,与像增强器极限分辨率相匹配,全视场畸变小于2 %,物镜总长达到67 mm。     

超大数值孔径光刻机投影物镜波像差检测方法

提出了一种基于空间像主成分分析的超大数值孔径光刻机投影物镜波像差检测方法。通过采用偏振光照明和矢量光刻成像模型并考虑投影物镜的偏振像差,准确表征了超大数值孔径光刻机的空间像,从而提高了像差检测模型的精度,实现了超大数值孔径光刻机投影物镜33项泽尼克像差(Z5~Z37)的高精度检测。相比于原基于空间像主成分分析的投影物镜成像差检测技术(AMAI-PCA)方法,所提方法适用于超大数值孔径光刻机投影物镜波像差检测。采用光刻仿真软件PROLITH对所提方法的检测精度进行了仿真验证,并分析了空间像采样间隔对波像差检测精度的影响。仿真结果表明,该方法对泽尼克像差(Z5~Z37)的检测精度优于0.85×10-3λ。     

光刻机投影物镜波像差检测技术研究新进展

本刊讯光刻机投影物镜波像差是影响步进扫描投影光刻机性能的重要指标,直接影响光刻机成像质量、光刻分辨率以及关键尺寸均匀性等关键参数。随着分辨率增强技术的不断进步和发展,光刻机投影物镜的数值孔径（NA）正逐步逼近其制造极限,这就要求波像差检测精度达到2mλ,     

Point defects on graphene on metals

Understanding the coupling of graphene with its local environment is critical to be able to integrate it in tomorrow's electronic devices. Here we show how the presence of a metallic substrate affects the properties of an atomically tailored graphene layer. We have deliberately introduced single carbon vacancies on a graphene monolayer grown on a Pt(111) surface and investigated its impact in the electronic, structural, and magnetic properties of the graphene layer. Our low temperature scanning tunneling microscopy studies, complemented by density functional theory, show the existence of a broad electronic resonance above the Fermi energy associated with the vacancies. Vacancy sites become reactive leading to an increase of the coupling between the graphene layer and the metal substrate at these points; this gives rise to a rapid decay of the localized state and the quenching of the magnetic moment associated with carbon vacancies in freestanding graphene layers.     

基于Matlab分析负荷对多联机IPLV的影响

多联机有其特殊的优点,但是不同部分负荷的组合对IPLV的影响仍需进一步研究。文中建立IPLV与部分负荷的相关公式,运用MATLAB软件分析不同卸载级负荷与IPLV的关系,从而确定不同部分负荷的最优组合。     

Remarks on KdV-type flows on star-shaped curves

We study the relation between the centro-affine geometry of star-shaped planar curves and the projective geometry of parametrized maps into RP¹. We show that projectivization induces a map between differential invariants and a bi-Poisson map between Hamiltonian structures. We also show that a Hamiltonian evolution equation for closed star-shaped planar curves, discovered by Pinkall, has the Schwarzian KdV equation as its projectivization. (For both flows, the curvature evolves by the KdV equation.) Using algebro-geometric methods and the relation of group-based moving frames to AKNS-type representations, we construct examples of closed solutions of Pinkall’s flow associated with periodic finite-gap KdV potentials.     

X-ray diffraction on chlorine adsorbed on graphite

Cl₂ layers adsorbed on Grafoil have been investigated by X-ray diffraction between 78 and 285 K. Mono- and submonolayers crystallize in a parallelogram lauttce, incommensurate with the (001) graphite surfaces, the molecules oriented almost perpendicular to the surface. The structure is closely related to that of the (001) planes of three-dimensional solid chlorine. For coverages above the monolayer completion bulk crystalization sets in.     

Note on duality on polarized symplectic manifolds

In this note we use some of the results of [3] to derive a general duality theorem for the cohomologies of foliated structures on a manifold. The result is applied to the special case of a symplectic manifold M on which the foliation is given by a complex polarization F in the sense of geometric quantization. We obtain, for example, a rigorous proof of the fact that for a smooth function ƒ on M whose Hamiltonian vector field leaves F invariant, the spectrum of the corresponding prequantization operator v(ƒ) coincides with the spectrum of its transpose, under the above duality. This latter result was obtained by Simms in [12] under certain hypotheses. Proofs of the validity of those hypotheses are now available in the literature; cf. [3] and [7].     

Space-charge effects on multipactor on a dielectric

Analyzes the effects of space charge shielding on the steady state of a multipactor discharge on a dielectric. Analytic methods are used to obtain an exact function for the potential in the discharge, assuming a Maxwellian distribution of emitted electrons. An equation for the amount of power deposited on the dielectric by the multipactoring electrons, for a given saturation level, is given. A simple method for obtaining the saturation level, for a given material, is obtained