首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
菲涅耳微透镜列阵衍射效率的测试与分析   总被引:1,自引:1,他引:0  
归纳了目前二元位相型菲涅耳微透镜列阵衍射效率测试中所用各种衍射效率的不同定义,提出规范定义的建议。并设计了测量衍射效率的系统,方法简单易行,适于测试具有微小单元尺寸的菲涅耳微透镜列阵的衍射效率。  相似文献   

2.
菲涅耳微透镜行列阵衍射效率的测试与分析   总被引:1,自引:0,他引:1  
归纲了目前二元位相型菲涅耳微透镜列阵衍射效率测试中所用各种衍射效率的不同定义,提出规范定义的建议。并设计了测量衍射效率的系统,方法简单易行,适于测试具有微小单元尺寸的菲涅耳微透镜列阵的衍射效率。  相似文献   

3.
线宽误差对菲涅耳透镜衍射效率的影响   总被引:3,自引:1,他引:2  
基于标量衍射理论,首先得出存在线宽误差情况下4阶菲涅耳透镜衍射效率的解析式;并以 4阶、8阶和16阶菲涅耳透镜为例,进行计算机模拟计算并系统分析线宽误差对菲涅耳透镜衍射效率的影响。通过实验测量16阶菲涅耳透镜的线宽误差,分析其对16阶菲涅耳透镜衍射效率的影响。模拟计算结果对多阶菲涅耳透镜的制作提供重要的理论指导。  相似文献   

4.
我们使用薄膜沉积法制作16阶菲涅耳透镜,其衍射效率接近87%.用它代替常规的光学透镜可实现系统的轻量化、小型化、增加系统设计的自由度.在标量衍射理论的基础上,应用菲涅耳公式和傅里叶变换分析SiO2薄膜和基底的表面反射、对准误差以及入射角对16阶菲涅耳透镜衍射效率的影响.  相似文献   

5.
消色差谐衍射微透镜列阵的应用研究   总被引:7,自引:3,他引:4  
本文研究菲涅耳谐衍射透镜的特性和工作条件,分析二元谐衍射透镜的衍射效率及制作要求,设计并研制了用于萨克-哈特曼波前传感器的双波长共焦谐衍射微透镜列阵,得到了良好的应用效果.  相似文献   

6.
表面反射对菲涅耳透镜的影响   总被引:1,自引:1,他引:0  
使用薄膜沉积法制作16阶菲涅耳透镜,用它代替常规的光学透镜可实现系统的轻量化,小型化,并增加系统设计的自由度,在标量衍射理论的基础上,应用菲涅耳公式和傅里叶变换分析SiO2薄膜和基底的表面反射对菲涅耳透镜-1级衍射效率的影响,结果表明表面反射对菲涅耳透镜的成像质量影响较大,可以通过蒸镀增透膜来减小这种影响。  相似文献   

7.
激光直接光刻制作微透镜列阵的方法研究   总被引:2,自引:1,他引:1  
杜春雷  徐平 《光学学报》1996,16(8):194-1196
介绍了利用激光直接光刻制作8相位台阶菲涅尔衍射微透镜列阵的工艺方法,并对元件的衍射效率及光刻过程中的制作误差进行了分析,透镜列阵在小形Shack-Hartmann波前传感器中得到了应用。  相似文献   

8.
杨俊波  苏显渝  徐平 《光子学报》2008,37(2):314-319
在8台阶、相位深度为2π的微闪耀光栅透过率函数的基础上,根据标量衍射理论分析了波长0.632 8 μm的He-Ne激光通过闪耀光栅发生菲涅耳衍射的复振幅分布,并得到了其满足1级闪耀输出的特点.将He-Ne激光通过8通道的微闪耀光栅列阵后菲涅耳衍射光场的分布规律与全混洗变换的特点相结合,得到微闪耀光栅列阵实现全混洗变换的周期公式.实验表明该微闪耀光栅列阵能够实现全混洗变换.  相似文献   

9.
本文基于小光点扫描,在国内首次提出了一种测试小F数衍射微透镜阵列光学性能的方法.利用光通信用半导体激光器和探测器建立了一套测试系统,并对所研制的大阵列,小单元尺寸的多相位菲涅耳衍射微透镜阵列的衍射效率和点扩散函数进行了测试.结果表明,衍射微透镜实际衍射光斑比理论衍射受限光斑扩展不大,8相位和16相位石英微透镜的衍射效率分别高达80.2%和87.5%,说明本实验室对多相位的设计理论和制作工艺已基本掌握,满足应用的要求.  相似文献   

10.
大数值孔径衍射透镜的优化设计方法   总被引:4,自引:0,他引:4  
安晓强  杜春雷 《光子学报》1998,27(5):453-458
本文针对大数值孔径衍射透镜工艺制作难的问题,以菲涅耳衍射透镜为例,研究了相位匹配原理并提出了一种优化设计二元大数值孔径衍射透镜的方法。在菲涅耳衍射透镜原理的基础上,确定了优化设计多相位台阶衍射透镜的结构参数,并给出了一个设计实例,最后对结果元件的衍射效率进行了分析与讨论。  相似文献   

11.
Sambhu N Datta 《Pramana》1993,41(4):345-362
A set of indigenously developed computer programs for ab-initio Hartree-Fock calculations on both closed- and open-shell molecules have been described. These programs have been written for calculations using GTO basis sets. Integral formulae have been taken from Taketaet al [8]. Structures and functions of the programs have been discussed. These programs have been extensively tested. Molecular integrals over GTO basis sets have been chosen for tests and as numerical examples in this paper. Results of calculations using very accurate minimal bases have been given for methane. Time taken for these computations in a CDC Cyber 180/840 machine has been indicated. Trends in the calculations have also been illustrated by employing 4-gaussian expansions for the STO’s and by varying the basis size for LiH and BH+. An erratum to this article is available at .  相似文献   

12.
Gopaljee  S N Chatterjee  B N Roy 《Pramana》1991,36(3):325-334
The binary encounter approximation has been used for calculations of electron impact single ionization cross-sections for F, Cl, Br and I and double ionization cross-sections for Br and I. Contributions of ionization from inner shells have also been included in the calculations. Hartree-Fock momentum distribution has been used for the bound electron as far as possible. The results have been found to be in satisfactory agreement with experimental observations.  相似文献   

13.
The hybridizations of a graphene layer by a thymine and a uracil nucleobase have been investigated by performing density functional theory (DFT) calculations. The isolated and hybrid structures have been firstly stabilized to reach the minimum energy and the electronic properties have been subsequently evaluated for the optimized structures. The structural and atomic scale parameters indicated that the tip of graphene is important in determining the properties of new hybrids. Moreover, different effects of thymine and uracil nucleobases have been identified in the hybrid structures. Quadrupole coupling constants have been evaluated to characterize the atomic scale properties, in which the most notable effects of hybridizations have been observed for the atoms close to the linking regions whereas negligible effects have been seen for other atoms.  相似文献   

14.
大口径光学元件薄膜厚度均匀性修正   总被引:2,自引:0,他引:2       下载免费PDF全文
 研究了2.2 m高真空箱式镀膜机镀膜时的实际膜厚分布情况。对非球面和平面光学元件,分别采用行星夹具和平面公转夹具并利用修正板调节膜厚均匀性。从实验上实现了大口径薄膜均匀性的调节,并获得较为理想的结果。口径在700 mm范围内,对于凹面均匀性可以控制在0.7%以内,平面均匀性在1%以内;口径在1 200 mm范围内凹面元件均匀性可控制在1%以内,平面1 300 mm口径以内窗口均匀性可控制在1%以内。镀制了口径在400~1 300 mm的多种天文观测上使用的反射镜、增透膜等,获得了理想的光谱曲线与较好的使用效果。  相似文献   

15.
A Fizeau interferometer-based set-up for measurement of surface figure of plane optical surfaces has been discussed. Phase-shifting interferometry has been applied using wedge phase shifter. Technique for elimination of system aberrations has been described. Results are shown for a plane surface.  相似文献   

16.
R. A. Yadav  I. D. Singh 《Pramana》2004,62(6):1255-1271
Electromagnetic theoretic analysis of shielded homogeneous and isotropic dielectric spheres has been made. Characteristic equations for the TE and TM modes have been derived. Dielectric spheres of radii of the order of μm size are found suitable for the optical frequency region whereas for the microwave region radii of the order of mm size are found suitable. Parameters suitable for their application in the optical and microwave frequency ranges have been used to compute the frequencies corresponding to the normal modes for the TE and TM modes. Expressions for the quality factors for realistic resonators, i.e., for a dielectric sphere with a non-zero conductivity and a metal shield with a finite conductivity have also been derived for the TE and TM modes. Computations of the quality factors have been made for resonators with parameters suitable for the optical and the microwave regions.  相似文献   

17.
A 1.25MV high-voltage electron microscope with a B-type omega filter has been successfully installed at Kyushu University. An image detection chamber has been set inside a concrete block below the ground level without changing the frame structure for anti-vibration. Nearly the same design as that for the 200kV microscope has been kept for the present omega filter except for its size. A new pre- and post-filter lens system with rotation-free imaging has been designed. Energy resolution, beam shape and stability of the filter have been measured. Some application data have been obtained to demonstrate the performance of the filter.  相似文献   

18.
The invariance of Dirac's equation under rotation has been used to obtain the wave equation for a particle interacting with an electromagnetic field. The origin of the anomalous magnetic moment of a particle has been attributed to the existence of mass due to spin. These masses for a few representative particles have been calculated. In particular these calculations give a mass of 592.074 eV for a neutrino. An operator for the spin angular velocity has been constructed and the values of spin angular velocities for the particles have also been calculated.  相似文献   

19.
This paper presents a general schema for classifying treatment approaches for both functional and organic voice disorders. It's use is illustrated by a review of treatments for Spasmodic Dysphonia. Most behavioral approaches have been found to be unsuccessful except for mild cases. Inhalation speech as a compensatory technique has been reported as somewhat successful for those mild/moderate cases for whom medical/surgical treatment has not been available. The fact that organic treatment levels have been more successful in the treatment of Spasmodic Dysphonia may lend support to an organic etiology  相似文献   

20.
Chiral smectic liquid crystal cells showing V-shaped electrooptical switching have been reported as one of the most promising technologies for high-end display applications. In this work, time-resolved electrical behaviour of these devices has been obtained through a set of systematic measurements. The electrical equivalent circuit has been derived, a number of simulations at different frequencies have been performed using commercial software for analogue circuits. Performance of this electrical model to account for time domain variations of switching currents in chiral smectic LC displays with V/W-shaped electrooptical response has been analyzed as well.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号