一维大气边界层光学折射率结构常数数值模式的实验检验

提出了一种大气光学折射率结构常数的数值模式。一次输入日期、时间、经纬度、温度、湿度、风速、粗糙度、土壤参数，云量等相关参数，可得到24h内的温度、湿度、风场、折射率结构常数等量。通过与实测对比表明，无论是月平均折射率结构常数还是某天的折射率结构常数，模式计算与实测数据都符合得很好。模式计算的向下总辐射量与实测数据基本一致。     

一维大气边界层光学折射率结构常数数值模式的实验检验

 提出了一种大气光学折射率结构常数的数值模式。一次输入日期、时间、经纬度、温度、湿度、风速、粗糙度、土壤参数，云量等相关参数，可得到24h内的温度、湿度、风场、折射率结构常数等量。通过与实测对比表明，无论是月平均折射率结构常数还是某天的折射率结构常数，模式计算与实测数据都符合得很好。模式计算的向下总辐射通量与实测数据基本一致。     

近地面层大气折射率结构常数的模式研究

 运用Bulk方法对东南沿海和合肥一水库附近的折射率结构常数进行了估算，为避免海边海盐对金属丝的污染，用高精度超声风速仪替代温度脉动仪测量折射率结构常数。模式主要输入的参数有气温、地表面温度、湿度、风速及测量点高度。结果表明：运用Bulk方法估算折射率结构常数是可行的，相似性函数分别采用Frederickson公式与Thiermann公式，差别不大；直接测量海面上折射率结构常数比较困难，通过输入海表面温度、海面上的粗糙度长度以及适合的相似性函数，可用于估算海面上的折射率结构常数。     

湿度起伏对可见光波段折射率结构常数的影响

大气折射率起伏主要是由温度和湿度起伏引起的。提出一种研究湿度起伏对折射率结构常数影响的新方法,即从超声风速计测量的虚温信号中提取出湿度起伏的信息,可计算出湿度起伏、温湿相关项的结构常数。采用自行研制的温度脉动仪和超声风速计分别在湿度差异较大的干燥的戈壁滩和潮湿的海边进行实验,并用实验时的气象参量对湿度起伏进行了模式计算。测量和模式计算都表明：湿度起伏本身对Cn^2的贡献很小,可忽略不计,湿度起伏对Cn^2的影响主要是通过与温度起伏相结合来实现的,在一般情况下,这种贡献不到10％。但在湿度较大,特别是日落前Cn^2处于最小值附近,温湿相关项的贡献可超过10％。     

陆地和近海面大气光学湍流估算与测量

基于Monin-Obukhov相似性理论,采用MARIAH算法,利用成都和茂名两个地区、两个高度层上的温度、湿度、风速等常规气象参数估算折射率结构常数,并对估算值与温度脉动仪测量值进行比较分析。结果显示:利用常规气象参数估算得到的成都与茂名的折射率结构常数在变化趋势及量级上基本符合温度脉动仪测量值。成都和茂名的折射率结构常数估算值与测量值的相关系数分别为0.86与0.92,平均绝对值偏差分别为0.410与0.414。因此,采用MARIAH算法估算陆地和近海面大气光学折射率结构常数是可行的;茂名中午时刻的折射率结构常数峰值比成都大一个量级。     

一维大气边界层光学折射率结构常数的数值模式

 提出了一种大气光学折射率结构常数的数值模式。通过解大气边界层风速、位温度、绝对湿度预报方程,表面热平衡方程和土壤热传导方程，得到地表温度、表面层的动量通量、显热通量和潜热通量。再由Monin Obukhov相似理论，从湍流通量和温度结构常数的经验关系计算出折射率结构常数。     

基于风廓线雷达的光波段折射率结构常数方法研究与理论仿真EI北大核心CSCD

湍流对光在大气中的传播有重要影响。光波段折射率结构常数是描述湍流强度的物理量。通过风廓线雷达回波分析是研究湍流强度的新方法。利用风廓线雷达计算出湍流耗散率和平均风的垂直梯度,结合温度、气压等常规气象参数,可估算光波段折射率结构常数,计算的量级在10-18～10-13 m-2/3之间,符合实际情况,证明了方法的可行性。同时对不同等压面上压强梯度、温度梯度及湿度对折射率结构常数的影响进行了数值计算。结果表明,同一等压面上压强梯度改变对Cn2影响很小,可忽略不计;而温度梯度改变对结果有较大影响,故对温度廓线的测量有较高的精度要求;相对湿度10%～90%的变化对光波段折射率结构常数的影响低于一个量级,因此在晴空大气条件下,湿度项可以忽略。     

一维大气边界层光学折射率结构常数数值模式的敏感性分析

 提出了一种大气光学折射率结构常数的数值模式。通过敏感性分析发现，对折射率结构常数有显著影响的参数是：一年中的不同日期、土壤的热容量和含水量、雪地和水面上、云量等，风速大小几乎对折射率结构常数没有什么影响。     

低平流层下温度结构常数和温度起伏谱幂率廓线的探空测量

两个不同空间距离上(r1=0.5m,r2=1m)温度结构常数廓线C2T(h)和温度起伏谱幂率廓线α(h)由探空仪获得。研制的湍流气象探空仪具有两个微温测量通道,可根据研究内容进行多种组合。除测量温度、湿度、压强、风速、风向、折射率结构常数C2n廓线、Fried参数r0、视宁度εFWHM、等晕角θ0和相干时间τ0等积分计算值外,还可得到高空湍流谱幂率廓线数据。谱幂率测量结果与Zilberman三层谱模式相比,在对流层顶以上有较大区别。这些结果对光传输、光通信、遥感和大气湍流建模等应用领域研究具有十分重要的意义。     

近海边高空光学湍流的探空测量与模式比较

 用自行研制的探空仪测量了近海边高空湍流廓线。探空气球携带微温传感器以4 m·s-1速度上升至20 km测量大气湍流，微温传感器附加在59型气象探空仪上，可同时测量垂直空间分辨率为30 m的气压、温度和湿度以及折射率结构常数。运用Tatarskii公式计算了高空湍流外尺度，分析了边界层湍流和自由大气层湍流特征。与AFGL AMOS模式、Hufnagel模式以及北京天文台兴隆站的探空拟合曲线进行的比较发现，海边测量的高空湍流强度比其它模式大2个量级，折射率结构常数随高度从表面层较大值以近似相同的递减率缓慢地减小，对流层顶附近没有出现较强的湍流区，外尺度测量值小于30 m，并得到外尺度的拟合曲线。     

GENERALIZED FRESNEL DIFFRACTION INTEGRAL AND ITS APPLICATIONS

Within the generalized definition of ABCDGH matrices, the conventional ABCDGH diffraction integral is extended for a misaligned complex paraxial system with a curved optical axis. On this basis the transformation law for Gaussian-Schell model beams through an ABCDGH systems is derived, the propagation behavior of the mutual coherence function through ABCDGH systems in the presence of random media is investigated as well.     

失调单球面折射系统的衍射积分和分数傅里叶变换

根据球面的几何特征，分析了单球面折射光学系统折射面倾斜和偏心时的失调特征；由失调元件矩阵和共轴元件矩阵的依次相乘，得到了完备的描述失调单球面折射光学系统的矩阵；从系统衍射积分与失调矩阵元的关系导出了该系统的失调衍射积分，并利用单球面折射光学系统的分数傅里叶变换结构参数得到了系统失调时的分数傅里叶变换结果.这些结果可用于数值计算和模拟该系统失调时对输入复振幅的衍射和分数傅里叶变换.     

Use of Dirac matrices in polarization optics

Several matrix methods have been developed for studying polarization properties of light. Jones was the first to apply the matrix method to the study of polarization optics. In Jones matrix formalism the polarized wave field is represented by 2-element column matrix known as Jones Vector and the polarization device encountered by light is represented by a 2×2 matrix, known as the characteristic Jones matrix of the device. Mueller introduced a new matrix method where the wave field is represented by a 4-dimensional vector. The elements of the vector are the Stokes parameters of the beam. In Mueller matrix formalism the optical device is represented by a 4×4 real matrix known as ‘Mueller Matrix’ of the device. The use of coherency matrix also proves to the useful in the study of partially polarized light. Pauli spin matrices have been used to unify the different matrix treatments of polarization optical phenomena. The present article is an attempt to unify the analysis of polarization phenomena using Dirac matrices used by Dirac in quantum mechanics. We have however redefined the set of Dirac matrices in terms of the Kronecher product of Pauli spin matrices.     

Determining Transport Properties of Complex Multiterminal Systems: S‐Matrix of General Tight‐Binding Periodic Leads

Calculation of the scattering matrix (S‐matrix) of a system allows direct determination of its transport properties. Within the scattering theory, S‐matrices relate amplitudes of incoming and outgoing waves in semi‐infinite leads attached to a scattering region. Recently, an assembly method to calculate S‐matrices of arbitrary tight‐binding systems connected to atomic chains has been proposed, were the S‐matrices of subsystems are used to obtain S‐matrix of the total system. In this paper, a new efficient method to obtain S‐matrices of general periodic leads is established, which can be used in the mentioned assembly method, allowing to address coherent quantum transport of arbitrary multiterminal systems with complex geometries trough Landauer‐Büttiker formalism. In addition, a new method to determine extended‐state band structures of general infinite periodic wires is presented, which exploits properties of the S‐matrix. Finally, these methods are used to obtain band structure of graphene arm‐chair and zig‐zag nanoribbons and transmission functions in three terminal Z‐shaped graphene nanoribbon structures.     

失调分数傅里叶变换及其光学作用

利用失调光学系统的衍射积分公式,分析了失调的Lohmann分数傅里叶变换光学系统和准非对称非均匀介质的衍射特性,得到了两者具有相同的失调衍射积分表达式,表明两者具有等效性,从中提出了失调分数傅里叶变换新概念. 关键词： 分数傅里叶变换 失调光学系统 衍射积分 梯度折射率介质     

Transformation matrices for the Mueller-Jones formalism

The Mueller-Jones (MJ) or pure Mueller matrix formulation has been reported by using two different matrix transformations in a condensed representation. The possibility to find other transformation matrices is explored. A complete set of unitary operators (R) is found to be closely related with the MJ matrices and with the evolution of pure states on the Poincaré sphere surface. We propose an alternative deduction for the condensed representation of the MJ matrices, obtained by using the Kronecker product operation and use of R unitary matrices as a tool to combine different Mueller matrices and changes of polarized states on the Poincarè sphere surface. Finally, it is shown explicitly that the columns of the transformation matrices are the eigenvectors of the MJ matrix associated to a non-depolarizing optical system and a corollary is established as a criterion to differentiate a Mueller matrix from an MJ matrix.     

A novel ray refraction matrix for curved interface

A problem in fundamental 2 × 2 ray matrix for refraction at curved interface proposed by A. E. Siegman was found out and a novel one was derived in this paper. An experiment is introduced in detail to verify the reasonability of the novel ray matrix. Using the novel 2 × 2 ray matrix, augmented 5 × 5 ray matrix of refraction at misaligned curved interface between media of different refractive indices was deduced. With the refraction matrix, it is easy to characterize the effect of an astigmatic thick lens. The augmented ray matrix approach was applied to model and estimate the performance of an optical alignment system. Utilizing these matrices, one can readily design and evaluate optical systems, where contain astigmatic elements such as tilted spherical or cylindrical lenses, mirrors and so on. These results are also useful for cavity design, alignment, ray tracing and beam position control in 3D optical systems.     

A real decoupled method and free interface component mode synthesis methods for generally damped systems

This paper reports on the development of a new transformation method. In contrast to most existing mode transformation methods in which the first-order state-space equation of the damped vibration system is transformed into a decoupled form with complex coefficient matrices, using the decoupled method presented in this paper, the equation of the damped system can be decomposed into a decoupled equation with real coefficient matrices. Two new free interface component mode synthesis methods are also presented. The equivalent full-mode matrix of the damped structure is used to capture the effects of the higher-order modes. Additionally, this work modifies the compatibility conditions at the junctions that are employed in most of the previous component mode synthesis methods for generally damped systems. The first component mode synthesis method is performed in complex space, whereas the second method can be applied in real space. Because the coefficient matrices of the coupled equation constructed by the second component mode synthesis method are all real-valued, the solution of the eigenproblem for this coupled equation can be performed in real space as well. Additionally, numerical examples demonstrate the accuracy and validity of these two component mode synthesis methods.     

Propagation of hollow Gaussian beam through a misaligned first-order optical system and its propagation properties

Propagation properties of hollow Gaussian beam through a misaligned first-order ABCD system is studied using the generalized Huygens-Fresnel diffraction integral, augmented matrix. It is shown that, as a hollow Gaussian beam passes through the misaligned first-order ABCD system, the beam shape is not preserved, the out-put beams have differences when passing different misaligned optical systems. We can adjust the size of dark region through adjusting the misaligned transverse vector E.     

Matrix Representation of the Stationary Measure for the Multispecies TASEP

In this work we construct the stationary measure of the N species totally asymmetric simple exclusion process in a matrix product formulation. We make the connection between the matrix product formulation and the queueing theory picture of Ferrari and Martin. In particular, in the standard representation, the matrices act on the space of queue lengths. For N>2 the matrices in fact become tensor products of elements of quadratic algebras. This enables us to give a purely algebraic proof of the stationary measure which we present for N=3.