Film thickness measurement by frustrated total reflection fluorescence

If the interface between a dielectric surface and an adjacent, fluorescing, medium of lower refractive index is illuminated by a collimated light beam, an exponentially decaying evanescent wave is generated in the fluorescing medium. The electric field of the evanescent wave generates easily measurable fluorescence. If part of the surface is covered with a dielectric film, the fluorescence generated is smaller, since some of the decaying wave occurs in a non-fluorescing medium. Measurement of the difference between the fluorescing signals enables the non-destructive measurement of the film thickness to be made. Several questions arise, for example (i) what angle of incidence should be used, (ii) how is the sensitivity influenced by the substrate refractive index, (iii) should p-or s-polarized light be used, (iv) what sensitivity is attainable? This paper answers these questions and indicates that films of the order of a nanometre in thickness are detectable.     

The study of the target emissivity and detection using a superconducting detector in the submillimeter wave region

This paper researches mainly the radiation characteristics of the target and detecting techniques by superconducting detector in the submillimeter wave(SMMW) region. The calculation of transition wavelength(TW) between Planck and Rayleigh-Jeans is given out. The experiment of detecting different targets is finished by use of superconducting detector possessing high performances. Through the experiments in paper we can select and determine the wave bands of SMMW detecting and imaging system. The many novel theoretical analyses and experimental results are expressed in Figs and tables of the paper. Finally, a part of calculating results and experimental datum detected by a superconducting detector in SMMW regions are given in this paper.     

法拉第手征介质反射电磁波的极化特性研究

从麦克斯韦方程出发严格推导了均匀介质与法拉第手征介质交界面处电磁波反射公式.通过解析的方法讨论了不同极化状态下反射电磁波的极化特性与法拉第手征介质电磁参数之间的关系.针对部分具体实例进行了计算,计算结果与理论预测相符合. 关键词： 法拉第手征介质 反射电磁波 极化特性     

光泵亚毫米波激光的理论模型及计算方法(Ⅱ)--多能级分子系统的激光增益系数

为了便于对光泵亚毫米波激光进行理论计算,从量子系统的密度矩阵方程出发,分别详细推导了三能级和四能级分子系统的激光增益系数表达方式以及多组独立三能级系统的增益迭加原理.     

涡旋光束在反射中的正交偏振特性研究

本文从角谱理论出发建立了涡旋光束在空气-玻璃界面反射时的傍轴传输模型, 并研究了反射过程中诱导产生的正交偏振效应. 当一水平偏振涡旋光束以不同角度入射时, 反射光束的正交偏振分量呈现出类似于一阶厄米-高斯模式的双峰强度分布, 而水平偏振分量强度分布呈现与入射光束相似的分布, 且只在布儒斯特角附近入射时才现出与正交偏振分量垂直的双峰分布. 对于任意线偏振入射光, 其正交偏振分量的偏振方向不再垂直于入射时的偏振方向, 而是与反射光束的中心波矢垂直, 此时正交偏振分量出现有趣的旋转特性, 其物理原因归结于任意线偏振光入射时所对应的水平与垂直偏振分量的反射系数不同. 最后进行了相关实验验证, 发现实验结果与理论分析符合得较好. 关键词： 正交偏振 涡旋光束 任意线偏振     

人工异向介质调控电磁波极化特性的实验与仿真研究

电磁波的极化特性在通信、导航和雷达等方面已逐渐得到应用.为了有效控制电磁波的极化状态, 本文设计了一种基于开口环结构的人工异向介质.该人工异向介质由开口环结构,电介质基底和金属背板组成, 可以将入射的线性极化波完整地转换为圆极化波,椭圆极化波以及和入射波极化方向垂直的线极化波. 本文通过实验和仿真验证了本文的设计,实验结果和仿真结果符合较好.     

电视导引头的激光回波分析

阐述了用激光主动扫描法侦察远方飞航导弹来袭方位的原理及实验技术。以电视导引头光学系统为例,运用矩阵光学追迹法对影响“猫眼效应”回波强度的因素进行了定性和定量的分析。研究结果表明:回波强度受导引头光路中光学镜头的相对孔径、摄像管靶面倾斜和离焦的影响较大;扫描激光光束的入射角等因素对回波强度也有一定的影响。在主动扫描装置与被探测导引头相距约5000m、扫描光束的入射角为0.1rad的条件下,导引头光学系统反射面倾斜和离焦使得侦察装置接收到的回波能量与发射脉冲能量之比由理想条件下的1.0%分别下降到了0.004%和0.3%。     

Extension of the range of resonator scanning spectrometer into submillimeter band and some perspectives of its further developments

Extension of the working frequency of modern resonator spectrometers into submillimeter wave range is described. Experimental record of atmospheric absorption spectrum covering 45-370 GHz range is demonstrated for the first time, and measured water vapor J′_{ka′, kc′}-J_{ka, kc} = 5_1,5-4_2,2 at 325 GHz line parameters are presented. For the first time pressure lineshift for the 325-GHz water vapor line is measured. Further extension of working range is discussed. New estimations of physical limits of time needed for measurements of absorption in the whole Backward Wave Oscillator (BWO) range are given for phase continuous synthesizer regime. Basic schemes of fast broadband continuous phase synthesized sources are discussed. Verification of the previous measurements of water vapor 3_1,3-2_2,0 at 183 GHz line parameters is presented. Comparisons with ringdown resonator spectrometers are given.     

一种基于新型偏振干涉成像光谱仪的目标偏振信息探测新方法

提出了一种采用基于视场补偿型Savart偏光镜的新型偏振干涉成像光谱仪对二维目标偏振信息进行空间遥感探测的新原理和新方法.在新型偏振干涉成像光谱仪光学系统不变的情况下,通过旋转偏振干涉仪分别测出了三个不同角度下像面上各像点的光强值,反演出了二维面目标的斯托克斯矢量,并给出了各像点偏振度和偏振方向的理论表达式.采用计算机模拟实验对该探测原理和方法进行了验证,所得结果与理论完全符合.从理论和实践上扩展了干涉成像光谱仪的探测功能,与目前国内外所研究的成像光谱仪相比,该成像光谱仪既能同时探测目标二维空间信息和一维光谱信息,又提供了一种获得目标偏振信息的手段和方法.     

Random error of determining light scattering matrix elements at various polarization states of probing radiation

Using the method of mathematical modeling, we consider the transformation of a random error of light intensity measurement into an error of determining elements of the light scattering matrix. We consider a device in which the polarization properties of probing radiation change depending on the setting of the phase plate and polarization analysis of scattered radiation is performed while the second phase plate located ahead of a stationary analyzer is rotated. A set of settings of the first phase plate has been revealed, which provides a minimum random error in determining the scattered light matrix elements. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 4, pp. 520–523, July–August, 2000.     

Quantum reflection as the reflection of subwaves

This paper studies quantum reflection with recent research on reflection coefficient. Based on the analytical transfer matrix method, a novel explanation for this phenomenon is proposed that quantum reflection is the reflection of subwaves, which originate inherently from the inhomogeneity of the fields and is always neglected in the semiclassical regime. Comparison with exact formula and the numerical calculations for different potentials has confirmed the reliability and the validity of the proposed theory.     

用琼斯矩阵法分析别汉棱镜像面偏振态分布

 基于反射定律的矢量式易于追迹复杂系统中光线的三维空间传播方向,计算了别汉棱镜每一面反射光线的方向,利用琼斯矢量法建立每一反射平面的琼斯矩阵以及面与面之间的传输矩阵,得到了一束线偏振平行光通过别汉棱镜后像面上的偏振状态分布,即经由2个屋脊面出射的光束是2个方位角不同的椭圆偏振光,这2个方位角的大小与入射线偏振光的振动方向有关。采用斯托克斯参量测量法,对别汉棱镜像面上偏振状态的分布进行了实验检测,得到了与理论分析一致的结果,指出别汉棱镜的偏振效应将会导致出射光束偏振状态的不均匀分布。     

非线性偏振旋转中偏振控制器方位角的研究

提出一种基于Jones矩阵的非线性偏振旋转锁模光纤激光器数值模型, 对偏振控制器波片方位角的描述具有物理意义清晰的优点. 数值仿真得到均方根宽度为0.28 ps的超短脉冲, 时域对称且振幅稳定. 搭建了非线性偏振旋转锁模光纤激光器, 系统可以自启动, 得到了重复频率为67.35 MHz的锁模脉冲输出. 数值仿真和实验结果都表明偏振控制器两个波片的方位角α₁和α₂都具有周期性, 周期分别为180°和90°. 由于随机双折射的影响, 实验测得的波片方位角调谐范围比数值仿真的结果小, 这一点通过在数值仿真模型中加入随机双折射的作用而得到证明.     

利用偏振干涉成像光谱仪进行偏振检测的最佳角度分析

利用偏振干涉成像光谱仪进行偏振探测,这一方法将偏振测量与干涉成像光谱技术相结合,一方面能提供辐射测量所不能提供的物体偏振信息,另一方面又可获取目标的空间图像和光谱,具有比辐射测量更高的准确度.在简要分析了利用偏振干涉成像光谱仪进行偏振检测的理论基础上,深入研究了偏振检测的方法,分析比较了目前常用的偏振探测角度（45°,60°）对偏振度探测的影响.进一步计算推导出偏振测量的最优探测角度,将之与以往常用的探测角度进行了分析比较,证明了此最佳探测角度可以有效地减小偏振误差、提高偏振探测的精度.这将极大地提高偏振干涉成像光谱仪的应用范围,为新型偏振干涉成像光谱技术的研究以及仪器研制提供重要的理论依据. 关键词： 偏振检测 偏振干涉成像光谱仪 探测角 Savart偏光镜     

光学教学中的偏振度定义

分析了当前国内部分光学教材中对偏振度定义的歧义,指出依照电矢量在不同方向上的强度来定义偏振度的不完整性,并由此提出教学中的注意点．     

Human skin as arrays of helical antennas in the millimeter and submillimeter wave range

Recent studies of the minute morphology of the skin by optical coherence tomography showed that the sweat ducts in human skin are helically shaped tubes, filled with a conductive aqueous solution. A computer simulation study of these structures in millimeter and submillimeter wave bands show that the human skin functions as an array of low-Q helical antennas. Experimental evidence is presented that the spectral response in the sub-Terahertz region is governed by the level of activity of the perspiration system. It is also correlated to physiological stress as manifested by the pulse rate and the systolic blood pressure.     

软X射线多层膜反射式偏振光学元件设计

叙述了软X射线波段反射式多层膜起偏器和检偏器的设计原则和设计方法,计算了不同波段软X射线反射式多层膜起偏器和检偏器的性能,讨论了多层膜制作过程中,表界面误差(表面粗糙度和扩散)对起偏器和检偏器性能的影响,探讨了光谱分辨率对偏振元件测试过程的影响,这些设计、计算和分析为制作实用软X射线多层膜偏振光学元件提供了理论基础。     

基于传输矩阵法讨论光疏介质表面的全反射

探究了光在光密介质与超薄光疏介质界面处的全反射,通过在光密介质中嵌入一光疏介质薄层,利用传输矩阵法,定量地分析了入射角度以及光疏介质的厚度对反射率的影响.数值模拟结果表明,当光疏介质的厚度小于约一个波长时,即使入射角大于全反射的临界角,反射率也不一定会达到1,也就是说,光学隧道效应将会出现.     

新型静态偏振风成像干涉仪理论探测误差的分析与计算

简述了新型静态偏振风成像干涉仪的原理,推导出一般情况下系统的Jones矩阵.在此基础上计算了系统中各偏振器件重要参数在非理想情况下对风速和温度探测结果的影响.利用计算机模拟对探测误差进行了分析,并按照系统精度要求从理论上提出了各重要参数的误差容限.该研究为新型静态偏振风成像干涉仪的研制、定标及后期数据处理提供了理论依据. 关键词： 静态偏振风成像干涉仪 Jones矩阵 方位角误差 相位延迟量误差     

Structural polarization properties of vector Gaussian beam in the far field

Based on the vector angular spectrum representation of optical beam and the method of stationary phase, the analytical TE and TM terms of vector Gaussian beam have been presented in the far field. By using the local polarization matrix, the polarization properties of the TE and TM terms in the far field are investigated, and it is found that the degree of their polarization is only determined by the spatial location. When the source is completely polarized, the TE and TM terms are both completely polarized in the far field. When the source is completely unpolarized, the TE and TM terms in the far field are partially polarized. The whole beam is also partially polarized except on the propagating axis. Moreover, the degrees of polarization of TE and TM terms are both larger than that of the whole beam.[第一段]