Corrective Plate With a Gradient Index Media in the Catadioptiric System

1IntroductionIthasbeenprovedthataradialgradientindexmediaplatehasthesameeffectasalens"'..Whenthethicknessoftheplateisextremelyhigh,andtheradiusisverysmall,itcanbeconsideredasanopticalwaveguide.Ithasalsobeenprovedthatalaminategradientindexmediaplatehassome…     

Novel high magnification zoom laser beam expander

At present ,beam expanding as a common shapingmethod has been usedin many applications suchaslaserradar[1],interference measure[2],lasers[3],laser holo-gram[4],x-ray optics[5],fiber optics[6]and so on.Zoombeamexpander has been used in more applications fo…     

3kW射频板条CO2激光器抛物面非稳波导腔研究

为了提高传统球面镜腔3kW射频板条CO2激光器光束质量,设计了新型抛物面镜负支非稳-波导混合腔;结合标量光束的瑞利-索末菲衍射理论与特征向量法,研究了大菲涅耳数下镜面类型对非稳波导混合腔光场传输特性的影响;利用矩形波导理论、1维近似分析得出了波导传输损耗及偏振情况。结果表明,将非稳方向输出镜和尾镜改为与光轴交点处曲率半径为R1=951.32mm和R2=1088.68mm的抛物镜面,能够避免尾镜漏光,可有效改善模式鉴别特性;常用波导电极镀膜材料中,镀铝电极内波导方向传输损耗最小,传输光场为x偏振的EH1模。采用电极镀铝的抛物面非稳波导腔能够降低损耗、提升光束质量。     

蓝光光学头中非球面物镜的设计

本文是关于蓝光光学头的核心元件--非球面物镜的设计讨论.文中论述了非球面物镜的设计理论、初始结构参数的确定以及如何利用zemax仿真;并介绍了光学头用非球面物镜的评价参数.设计的物镜在有视场角的情况下仍然很好的符合使用要求.     

Array of hexagonal Fresnel zone plate lens antennas

An array of overlapping single-zone hexagonal Fresnel zone plate lens antennas was designed and tested at 30 GHz. By arraying smaller-diameter lenses, a significantly lower overall profile can be achieved compared to a single lens of equivalent diameter. These arrays can also find use in spatial power combining or in imaging applications.     

Focusing characteristics of curvilinear half-open Fresnel zone plate lenses: plane wave illumination

A diffraction field-focusing equation based on a specific conical-segment linearization procedure is derived for the Fresnel zone plate (FZP) lens of arbitrary curved profile and is applied for contrasting plane, spherical, parabolic and conical zone plate lenses, convex-side illuminated by a paraxial plane wave front. Two sets of 100-GHz curvilinear and plane FZP lenses are studied numerically with regards to their dimensions, axial focusing intensity and footprint, and frequency bandwidth. For the first set , where the curvilinear and plane lenses share a common lens base aperture and have equal focal lengths, the following new finding has resulted: regardless of their different in shape profiles the FZP lenses have equal zone numbers and produce similar axial focusing. The second set also consists of plane, spherical, parabolic and conical lenses. They share a common apex, and have equal in diameter base apertures and focal lengths but different thicknesses. For such disposition and proportions, the FZP lenses possess different zone numbers and focusing parameters (gain, efficiency, footprint and bandwidth). The belief that the curvilinear FZP have superior (or inferior) electromagnetic characteristics, compared to those of the plane FZP lens with equal number of zones is not in general true. Their relative focusing qualities can vary significantly depending on the lens positioning and dimensions.     

基于不同人眼模型的非球面人工晶体光学性能研究

为改善人工晶体植入眼成像质量,以多组角膜球差平均值为需补偿值,设计了前表面为非球面的双凸型非球面人工晶体。通过Zemax光学设计软件实现光线追迹的方法,基于不同人眼模型,将所设计非球面人工晶体植入,对相应眼光学系统的的成像质量进行分析,成像质量以假晶体眼光学系统的调制传递函数(MTF)和对比敏感度函数(CSF)表征。结果表明,植入本文设计的非球面人工晶体各模型眼的MTF曲线和CSF曲线均高于植入球面人工晶体;与目前临床上实际应用的LI61U型、Tecnis Z9000型和SofPort AO型3种人工晶体性能进行了对比分析,模拟分析模型为Liou眼系统,植入晶体屈光度为22D的结果表明,植入本文设计的非球面人工晶体眼光学系统的MTF和CFS曲线均高于植入其他3种晶体眼光学系统,所设计的非球面人工晶体表现出了相对优异的光学性能。     

多层介质型太赫兹菲涅尔天线研究

基于菲涅尔波带片透镜的设计原理,设计了三款多层介质结构的菲涅尔波带片天线.该天线采用高增益的波纹喇叭天线提供馈电,工作频段为太赫兹通信第一大气窗口320～380GHz,回波损耗低于-15 dB,增益大于25 dBi.研究了菲涅尔波带片天线的周期数和子区数对天线性能的影响,结果表明随着周期和子区数的增加,增益也会不断的提高,而当波带片直径和喇叭口径面积相比拟时,电磁波损耗较大,并且谐振频率在太赫兹大气窗口内右移.     

Compound Fresnel Zone Lens Conformal to Truncated Cone: Antenna Application

A millimeter wave antenna consisting of two Fresnel zone plate lenses, plane and conical, is examined numerically by use of the vector diffraction theory. The lenses are of Wood-Wiltse (double-dielectric) or Soret (half-open) type, and are designed for the frequency of 117 GHz. The lenses are made conformal to a truncated circular cone with a base diameter of 500 mm and a plateau diameter of 250 mm. Designs for two opening semi-angles, 45° and 75° each of them with a particular lens thickness are presented. For the angle of 90° the cone lens becomes a plane ring lens, which in combination with the plateau zone lens forms a plane lens of size equal to the cone base diameter. Illuminated by directive feeds set at a focal distance of 525 mm from the cone apex, the double-dielectric and half-open compound and plane lenses, form three pairs of Fresnel zone lens antennas, the co-polar and cross-polar radiation characteristics of which have been compared numerically. The double-dielectric lens antennas examined are about 5 dB superior in gain to the half-open lens antennas, which has a gain of approximately 45 dBi. Because all lenses are of equal transverse aperture, the corresponding lens antennas exhibit the same ?3 dB beamwidth of about 0.33 degrees. The plane zone lens antenna is very thin and simple. Instead, the antenna comprising a 3-D compound Fresnel zone lens is thicker but can be made conformal to a specific surface shape and possesses more levels of design and optimization freedom.     

相位阶跃变化型太赫兹波带片

对相位阶跃变化型太赫兹波带片衍射效率进行了理论研究。根据标量衍射理论,相位阶跃变化型波带片可以完成对高斯光束太赫兹波的聚焦。相位阶跃变化型波带片的衍射规律与薄透镜聚焦的规律相似。对其在光轴以及焦平面上太赫兹强度分布及衍射效率进行了模拟,通过与相位连续变化型,台阶型波带片的衍射效率进行对比分析,结果表明相位阶跃变化型波带片具有更好的衍射效率和性能。计算了一种相位阶跃变化型太赫兹波带片的加工尺寸,适合微机械加工法,有很好的应用价值。     

A Comparison of the Focusing Properties of a Fresnel Zone Plate With a Doubly-Hyperbolic Lens for Application in a Free-Space, Focused-Beam Measurement System

A Fresnel zone plate is designed to perform the function of a doubly-hyperbolic lens. The focusing characteristics of the zone plate and the lens are compared using both measured data and body-of-revolution finite-difference time-domain simulations. The results from this comparison are used to evaluate the use of zone plates as focusing elements in a free-space, focused-beam measurement system. A set of two zone plates is used to perform measurements of the material properties of a dielectric sheet, and the results are compared to the results from a standard system which uses two doubly-hyperbolic lenses.      

全息光栅法测凹面反射镜焦距

本文报道了一种利用全息光栅测量凹面反射镜焦距和球面反射镜曲率半径的新方法.这种方法测量精度高,不仅适合于球面反射镜,而旦特别适合于各类非球面反射镜焦距的非接触测量。     

伽里略非球面透镜扩束器

在激光系统中，伽里略球面透镜扩束器已得到广泛地应用，但是，它有许我乐足之处。本文中，研究了伽里略非球面透镜扩束器，给出了伽里略非球面透镜扩束器光学系统设计的方法和设计结果。我们得出的结论是：伽里略非球面秀镜扩束器比伽里略球面透镜扩束器好。     

Reference Phase in Diffractive Lens Antennas: A Review

We review a free parameter in the design of Fresnel zone plate lens antennas. Historically, zone plate antennas have been designed with a specific choice for this parameter, which can be taken as a type of phase reference. Two methods of interpreting the parameter have been identified, either in terms of a reference radius or equivalently a reference phase. Here, for simplicity, we treat this variable parameter as a reference phase. Importantly, the reference phase can be chosen to have non-standard values which have been shown to improve important aspects of antenna performance and to add a new functionality to zone plate antennas.     

双包层光纤激光器泵浦光耦合及激光反馈研究

总结分析了高功率双包层光纤激光器的泵浦耦合及激光反馈方式,指出了相关方式中应采取的一些措施.结果表明,采用树枝状结构多模耦合器进行侧向泵浦及采用光纤光栅进行激光反馈是最佳方式.同时特别指出菲涅耳波带片耦合方式的潜在优势,并提出采用镀二色膜等厚球透镜作为双包层光纤激光器腔镜以避免直接端面泵浦对腔镜膜的损坏.     

Indoor signal focusing by means of Fresnel zone plate lens attached to building wall

A simple inexpensive on-wall Fresnel zone plate (FZP) lens for indoor focusing of microwave signals is studied. It consists of concentric metal rings mounted on the outside of an exterior building wall. In our theoretical and empirical work the on-wall FZP lens is illuminated normally by a plane or spherical wave, of vertical or horizontal polarization, but other, more general incidence situations can be treated by similar means. The scalar quasi-optical focusing theory of the free-space zone plate has been modified and used for design and analysis of one-, two-, and three-ring on-wall FZP lenses. It is found that the presence of the wall does not change the FZP lens focusing efficiency significantly, but it has a strong axial defocusing effect. A 2-GHz FZP lens assembly consisting of three metal rings made out of thin antimosquito mesh has a focusing efficiency of about 15 dB (measured) and 14 dB (calculated), and axial defocusing of about 0.22 m. Some variations of on-wall/on-roof FZP lenses and their feasible applications in the microwave/millimeter-wave communication links are also discussed.     

无透镜隐形条型码的研究

提出了一种新型光学衍射条型码 (DOBC)。该条型码所包含的信息不是通过扫描器对条码的宽度、位置直接阅读而获得 ,而是通过光的衍射在其第一衍射级上显示而得到 ,此种条型码的外形看不出其内容 ,故称为隐形条型码。并提出一种制作隐形条型码的方法 ,利用菲涅耳波带片调制 ,制作成具有自聚焦功能的隐形条型码。对该隐形条型码进行了测试分析 ,并与用其他方法制作的隐形条型码进行了比较 ,实验结果表明其实际应用的可行性 ,且效果比其他方法要好     

结合CGH与辅助透镜的长焦距非球面反射镜检测（特邀）

目前,一些大口径光学望远镜主镜的曲率半径已经达到了几十米量级,若单纯利用计算全息实现对镜面进行面形检测,则检测光路长度不低于其曲率半径长度。受场地大小及环境气流扰动等因素的限制,该条件下难以实现对镜面的高精度测量。为了解决大口径长焦距光学镜面的高精度面形检测问题,提出了一种混合补偿干涉检测方法。该混合补偿方法结合了计算全息图和辅助透镜,在有效地缩短检测光路长度的前提下,可以实现对非球面镜面的零位补偿干涉测量。在光路设计中,需要有效地实现混合补偿光路光学设计参数优化以及对CGH衍射级次的分离;同时,检测光路长度应小于非球面反射镜曲率半径大小,以实现缩短检测光路长度的目的。通过对EELT主镜镜面进行仿真检测,结果表明:该方法检测光路长度可缩短至镜面曲率半径长度的1/8以内,设计检测精度优于RMS λ/100 （λ=632.8 nm）。上述仿真结果证明了该方法可以在缩短检测光路长度的情况下实现对待测非球面反射镜的高精度面形检测。     

非球面变焦扩束系统的设计

文章讨论了如何将二次旋转非球面透镜引入变焦扩束系统设计中,并给出了一个采用非球面透镜的变焦扩束系统的设计方案和参数。这个扩束系统的扩束比可在2．3－18之间连续改变,最大角差小于03mard。与采用球面透镜的扩束系统相比,非球面透镜的采用不仅可以简化系统的结构,而且可以取得更大的变焦范围,并使输出光束的质量有较大提高。     

高倍聚光光伏可拆卸型二次反射镜设计与研究

高倍聚光光伏技术是将垂直入射于菲涅耳透镜上的太阳光聚焦到电池片上,通过光电转换产生电能,但实际应用时,由于跟踪器跟踪精度低、支架受风会抖动等因素存在,无法保证太阳光始终垂直入射于菲涅耳透镜。针对该问题,在菲涅耳透镜和太阳能电池之间增加一个可拆卸的倒置的去掉顶部的棱锥形二次反射镜来提高聚光光伏的接收角,给出了具体的设计实例,并应用Solidworks软件和Tracepro软件对设计实例进行了计算机光学模拟。结果证实该二次反射镜能很好地提高聚光光伏的接收角,并改善菲涅耳透镜聚焦光斑的能量均匀性。