菲涅尔区修正圆柱面天线的辐射特性

在圆柱面上进行一维菲涅尔区相位修正结构设计，可以构成一类新型的点源馈电透镜天线。本文利用矢量场绕射理论研究菲涅尔区修正圆柱面天线的辐射特性，并进一步分析馈源阵列作用下的辐射性能。文中天线远场方向图的计算结果与有关文献中的结果吻合。     

Astigmatism-corrected miniature czerny-turner spectrometer with freeform cylindrical lens

A miniature, broadband, astigmatism-corrected Czerny-Turner spectrometer is proposed. Theories of the broadband astigmatism correction using freeform cylindrical lens are thoroughly analyzed. Comparisons of the freeform cylindrical lens method with those of titling cylindrical lens or wedge cylindrical lens methods are also described. Results show the better spectrometer performance with the new optical design over a broadband spectral range from 300 to 800 nm.     

Simple and high efficient optical trapping using a cylindrical lens and a single plane wave of incidence

We suggest a simple and high efficient method for trapping particles in the evanescent field. In this method, a single plane wave is normally incident on the cylindrical surface of a cylindrical lens and then incident on the plane surface of the lens at an angle larger than the critical angle. Multiple reflections of light within the cylindrical lens create two evanescent waves with different directions in the transmitted field. Interference of two evanescent waves comes into being a standing wave which can stably trap particles close to the top of the cylindrical lens. Based on the Rayleigh approximation, we obtain analytical expressions of optical force acting on a Rayleigh particle placed in the vicinity of the lens. We find that the trap stiffness and trap depth is dependent on the radius of the cylindrical lens, wavelength and polarization of light, and incident angle at the lens–liquid interface.     

小半径柱面镜光学加工工艺研究

针对某新型导弹激光系统提出的小半径柱面镜,通过对传统柱面镜加工方法的综合分析比较,选择合适的加工方法、用不同抛光模层进行抛光比较,对多种分离器材料和分离器槽的长短、模具的摆动幅度等进行工艺试验,使小圆棒柱面镜的表面粗糙度最小值达到Ra 0.005 m,优于设计图纸表面粗糙度Ra 0.01 m的要求,后续再磨去多余的半个圆柱,形成并达到平面的技术要求,满足了此半圆柱状的小半径柱面镜全部技术条件,形成稳定批产加工能力。     

一种自聚焦透镜的成像解

自聚焦锥透镜与圆柱透镜相比较，有其特殊之处。柱透镜在近轴平行光入射时，光线的振幅、相位、周期保持不变，而锥透镜的三者均发生变化，而且求解锥透镜的光线方程也比圆柱透镜复杂得多。本文推导了一个锥透镜的光线方程。可据此设计经过锥透镜后的光源大小，这在微系统照明中非常有用。     

替代柱面透镜的二元光学元件设计

在二极管泵浦固体激光器耦合光学系统中，柱面透镜起着非常重要的作用。随着系统轻量化、小型化的要求需要用重量轻、尺寸小的光学器件来替代。本文介绍一种用于替代柱面透镜的二元光学元件的设计和制作方法。     

柱透镜聚焦高阶Bessel光束产生焦散光束

研究了高阶Bessel光束经过柱透镜后的光场分布特性.在广义惠更斯-菲涅尔衍射积分理论基础上,推导出高阶Bessel光束透过柱透镜后的衍射光场分布表达式;并利用MATLAB和MATHCAD模拟了不同传播距离处的光强分布.实验上,利用轴棱锥和螺旋相位板产生不同阶数的高阶Bessel光束,并使产生的高阶Bessel光束经过柱透镜,最后用CCD记录下不同距离处的衍射光场.研究结果表明,高阶Bessel光束经过柱透镜形成唇状的焦散光束.     

线激光束均匀化整形方法研究

为解决核物理工程、表面热处理、激光加工、激光通信中传输激光束的均匀性问题,提出采用三角楔柱透镜改善线激光均匀性的新方法,并在ZEMAX开发环境下建立了整形光路系统的理论模型。利用所建立的模型,分析了整形柱透镜在不同半径、斜面夹角、透镜介质折射率等参数下光束的均匀性。研究表明：在远场条件下,通过改变整形柱透镜的参数,能够得到能量分布均匀的线激光。在实际应用中,可以采用1个半圆柱和2个相同三角楔胶合成型的简单工艺。进一步模拟发现,两种整形系统所得到的均匀度和线宽一致。     

Application of millimeter-sized polymer cylindrical lens array concentrators in solar cells

A unique method is proposed to encapsulate solar cells and improve their power conversion efficiency by using a millimeter-sized cylindrical lens array concentrator. Millimeter-sized epoxy resin polymer(ERP) cylindrical lens array concentrators are fabricated by the soft imprint technique based on polydimethylsiloxane stamps. The photovoltaic measurements show that millimeter-sized ERP cylindrical lens array concentrators can considerably improve the power conversion efficiency of silicon solar cells. The validity of the proposed method is proved by the coupled optical and electrical simulations. The designed solar cell devices with the advantages of high-efficiency and convenient cleaning are very useful in practical applications.     

Influence of the edge field on the focusing properties of a coaxial cylindrical lens

The effect of the distance between the grounded flat entrance diaphragm and the outer cylindrical electrode (which determines the edge field of the lens) is investigated over a wide range of variation of the geometry of a coaxial cylindrical lens. It is found that focusing of a charged particle beam on the lens axis is achieved over a wide range only in the case of small clearances between the diaphragm and the outer electrode. It is shown that for an alternative power feed arrangement, in which the outer cylindrical electrode is grounded and the voltage is applied to the inner electrode, beam focusing is in general degraded, in particular on the lens axis. Zh. Tekh. Fiz. 68, 124–127 (June 1998)     

Toward sub‐micro‐XRF working at nanometer range using capillary optics

Capillary optics are used for X‐ray fluorescence micro‐analysis using the Cu Kα line provided by a rotating anode. The excitation beam is focused using a polycapillary lens on a Co–Ti sample. Cylindrical glass capillaries of various diameters are fitted to the X‐ray detector (Energy Dispersive X‐Ray (EDX) analyzer) and displaced along the irradiated zone of the sample. The fluorescence is studied as a function of capillary position. Good agreement is found between experimental and calculated lateral widths of the fluorescence collection, taken into account the cylindrical capillary critical angles relevant in the experiment. The influence of the cylindrical capillary diameter on the signal level detected is studied to estimate the possibility of lateral resolution increase of X‐ray fluorescence technique both in‐lab and in synchrotron environment. Copyright © 2013 John Wiley & Sons, Ltd.     

柱面透镜准直LD光场的计算建模方法研究

为了简化LD光场准直柱面透镜繁琐的理论设计过程,便于进行实际操作,利用Matlab计算建模的方法,计算理想准直柱面透镜上的各个离散点的坐标值,通过拟合或二次曲面方程逼近的方法来获得准直柱面透镜的面型参数。分析表明,二次曲面柱面透镜非常适合做半导体激光器的准直透镜,可以根据具体需要来选择相应的面型。相比于其他方法,该方法简单直观,易于设计和加工,参数的优化调整迅速,可以根据加工工艺的难易程度来选择合理的透镜参数。     

Fabrication of cylindrical lens arrays utilizing the pinning effect of the partition walls on ultraviolet curable polymers

A technique of controlling the pitch and radius of curvature of a cylindrical lens array is presented. The lens pitch is controlled by producing the linear partition walls that sandwich a UV-curable polymer. The partition walls are created by scratching a polymeric substrate with a sharp edge. The radius of curvature can be controlled by designating the volume of the UV-curable polymer dispensed between the partition walls that prevent the spreading of the polymer due to the pinning effect. This technique can contribute to realizing a practical fabrication method for cylindrical lens arrays owing to its simplicity and flexibility.     

毛细管干涉仪的理论分析

从几何光学出发,推导了毛细管干涉仪的从柱面透镜到接收屏的光线的光程．对光线追迹模拟,结果表明毛细管干涉仪的干涉条纹的形成可用双光束的干涉来解释．从柱面不同位置入射的两条光线可能具有相同的光程,而且从柱面透镜不同位置出发的两条光线可能到达接收屏的同一点,当它们满足相干条件时,就会形成干涉条纹．建立了干涉条纹的计算机模拟程序, 模拟了毛细管中液体折射率、毛细管内径、外径对干涉条纹的影响. 结果表明实验中应使用薄壁毛细管, 由于干涉条纹对柱面透镜到毛细管之间的距离非常敏感, 为提高精度, 建议在实验中用已知折射率的标样来确定这一距离.     

检测柱透镜象差的全息干涉法

本文提出一种检测柱透镜象差的全息干涉法。文中详细介绍了全息干涉法的原理,具体实验以及有关调整问题。整个过程操作方便,光路按排简单。     

Acoustic radiation from a shell-encapsulated baffled cylindrical cap

An exact study of radiation of an acoustic field due to radial/axial vibrations of a baffled cylindrical piston, eccentrically positioned within a fluid-filled thin cylindrical elastic shell, into an external fluid medium is presented. This configuration, which is a realistic idealization of a liquid-filled cylindrical acoustic lens with a focal point inside the lens when used as a sound projector, is of practical importance with a multitude of possible applications in underwater acoustics and ocean engineering. The formulation utilizes the appropriate wave field expansions along with the translational addition theorems for cylindrical wave functions to develop a closed-form solution in the form of an infinite series. Numerical results reveal the key effects of excitation frequency, cap angle, radiator position (eccentricity), dynamics of the elastic shell, and cap surface velocity distribution on sound radiation.     

采用衍射掩模产生白光横向平顶光束

白光横向平顶光束在定向背光式自由立体显示器中有重要应用.本文提出一种采用带蝶形小孔阵列的衍射掩模片获得白光横向平顶光束的方法.根据广义惠更斯-菲涅耳衍射积分和多波长叠加原理,推导出光强分布计算式.设计一套实验装置,数值模拟并实验验证出射光束在不同距离的横向光强分布以及小孔蝶形凹度(蝶形中心高度与边长的比值)对横向光强分布的影响.结果表明:当选择小孔蝶形凹度为0.50—0.66时,可以得到平顶因子F 0.89的白光横向平顶光束,横向平顶光束的宽度随着传输距离的增大而增大,而平顶因子基本不变.实验还发现柱面透镜的折射色散和衍射色散可以互相抵消,使白光横向平顶光束基本无色散.     

基于蜷曲空间结构的近零折射率声聚焦透镜

研究基于蜷曲空间结构的近零折射率声聚焦透镜.根据近零折射率材料的声波方向选择机理,采用蜷曲空间结构为基本单元进行排列,设计具有特定入射与出射界面的几何结构,对透射声波的出射方向进行调控,实现了平面声波与柱面声波的聚焦效应,并深入讨论了透镜内部刚性散射体对声聚焦性能的影响.在此基础上,改变近零折射率透镜的出射界面,可以精确调控声波阵面的形状与方向.该类型透镜具有单一的单元结构、高聚焦性能及高鲁棒性等优点.研究结果为设计新型近零折射率声聚焦透镜提供了理论指导与实验参考,同时也为研究声波阵面的调控提供了新思路.     

高功率半导体激光器光纤耦合实验研究

为进一步提高光纤耦合半导体激光器的输出功率,提出了一种多单管半导体激光器通过台阶分布、光束精密准直及自由空间合束实现高功率光纤耦合输出的方法,该方法具有结构简单、光学元件易于加工、耦合效率高等优点。采用这种方法对5只封装在次热沉上的单管半导体激光器开展了芯径100μm、数值孔径0.22多模光纤的耦合实验研究,当工作电流为7.0 A时,光纤连续输出功率为21.8 W,亮度为1.83 MW/(cm~2·sr),耦合效率为70.32%。     

扭转对称光束的产生及其变换过程中的轨道角动量传递

研究了采用扭转柱面镜光学系统将厄米-高斯光束变换成为具有轨道角动量的拉盖尔-高斯扭转对称光束. 采用本征模式分解的方法分析了扭转柱面镜光学变换系统实现光束变换的原理.利用光束传输矩阵和二阶矩理论分析计算了光束经过扭转柱面透镜变换过程中的轨道角动量传递过程，证明光束与透镜系统的轨道角动量交换发生在第一个柱面透镜处，光束经过第一个柱面透镜后，具有的轨道角动量保持不变. 关键词： 轨道角动量 光束变换 扭转对称光束 轨道角动量传递