共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
The generalized Lorenz-Mie theory in the strict sense describes the interaction between an illuminating arbitrary shaped beam and a homogeneous sphere characterized by its diameter d and its complex refractive index m. It relies on the method of separation of variables expressed in spherical coordinates. Other generalized Lorenz-Mie theories (for other kinds of scatterers) expressed in spherical coordinates are available too. In these theories, the illuminating beam is expressed by using expansions with expansion coefficients depending on some fundamental coefficients named beam shape coefficients, more specifically spherical beam shape coefficients. In this paper we present a general formulation for the transformation of spherical beam shape coefficients through rotations of coordinate systems. 相似文献
3.
4.
G. Gouesbet 《Optics Communications》2007,278(1):215-220
The (electromagnetic) generalized Lorenz-Mie theory describes the interaction between an electromagnetic arbitrary shaped beam and a homogeneous sphere. It is a generalization of the Lorenz-Mie theory which deals with the simpler case of a plane wave illumination. In a recent paper, we consider (i) elastic cross-sections in electromagnetic generalized Lorenz-Mie theory and (ii) elastic cross-sections in an associated quantum generalized Lorenz-Mie theory. We demonstrated that the electromagnetic problem is equivalent to a superposition of two effective quantum problems. We now intend to generalize this result from elastic cross-sections to inelastic cross-sections. A prerequisite is to build an asymptotic quantum inelastic generalized Lorenz-Mie theory, which is presented in this paper. 相似文献
5.
离轴多层球对高斯波束的光散射 总被引:2,自引:2,他引:0
根据广义米氏理论,将入射的高斯波束按矢量球谐函数展开,获得了波束因子(展开系数)gmn,TM和gmn,TE的一般表达式。应用gmn的局域近结果和散射系数anm和bnm的迭代公式与算法,研究了多层有耗介质球的光散射。讨论了波束宽度与球形粒子的尺寸和位置对散射系数和散射强度角分布的影响。 相似文献
6.
This paper is the fourth of a series devoted to the transformation of beam shape coefficients through rotations of coordinate systems. These coefficients are required to express electromagnetic fields of laser beams in expanded forms, for instance for use in some generalized Lorenz-Mie theories. The main result of Part I has been the theorem of transformation of beam shape coefficients under rotations. Part II dealt with the special case of on-axis axisymmetric beams. Part III dealt with other special cases, namely when the Euler angles specifying the rotation are given some special values. The present Part IV studies another special case, namely the one of plane waves viewed as special on-axis axisymmetric beams, and can therefore be viewed as a special case of Part II. Unexpectedly, it is found that, in general, although plane waves are fairly trivial, their expansions require using non trivial beam shape coefficients, exactly as required when dealing with arbitrary shaped beams. 相似文献
7.
Grard Gouesbet 《Particle & Particle Systems Characterization》1994,11(1):22-34
Many optical sizing techniques rely on particle/laser interactions. The classical Lorenz-Mie theory describing sphere/plane wave interactions is therefore misleading when designing instruments and processing data when the particle size is not small enough with respect to beam diameters. In such cases the use of the generalized Lorenz-Mie theory is required. After summarizing essential features of the generalized Lorenz-Mie theory for sphere/arbitray wave interactions, this paper describes applications of the theory with some emphasis on the analysis of phase-Doppler anemometers. 相似文献
8.
基于广义Mie理论, 研究了椭球粒子对在轴入射的拉盖尔-高斯光束的散射特性. 通过局域近似法求解椭球坐标系中的波束因子, 计算得到了波束因子之间满足的普遍关系. 对散射强度随椭球粒子不同尺寸参数和扁圆程度的变化特性进行了数值计算, 并针对不同拓扑荷时的散射强度进行了对比分析. 结果表明: 当椭球粒子尺寸在与入射光波长可比拟的范围内变化时, 散射强度随尺寸参数的增大而增大, 随椭球长短轴之比和拓扑荷的增大而减小. 本文的理论研究能够为拉盖尔-高斯光束在粒径测量、大气激光通信、 大气遥感等领域的应用提供更准确的粒子模型和参考价值.
关键词:
椭球粒子
拉盖尔-高斯光束
波束因子
散射强度 相似文献
9.
10.
11.
This paper is the fifth of a series of papers devoted to the transformation of beam shape coefficients through rotations of coordinate systems. These coefficients are required to express electromagnetic fields of laser beams in expanded forms, for use in some generalized Lorenz-Mie theories, or in other light scattering approaches such as Extended Boundary Condition Method. Part I was devoted to the general formulation. Parts II, III, IV were devoted to special cases, namely axisymmetric beams, special values of Euler angles, and plane waves respectively. The present Part V is devoted to the study of localized approximation and localized beam models, and of their behavior under the rotation of coordinate systems. 相似文献
12.
根据广义Mie理论,研究了具有轨道角动量拉盖尔-高斯光束(LGB)的空间传输特性以及单粒子散射特性.在单体球粒子对高斯光束散射研究的基础上,分析了在自由空间不同传输距离LGB光束的光强分布情况,在不考虑散射和波束相移关系的情况下,将LGB作为入射高斯光束,通过对波束入射时的散射衰减截面求解得到波束因子,利用矢量球谐函数对入射高斯波束进行展开,从而研究了单球粒子在在轴条件下对具轨道角动量高斯波束入射的散射问题.通过数值计算,讨论了散射强度及角分布在不同波束宽度情况下对其散射特性的影响,并与平面波的情况做了对比.结果表明,当波束束腰半径较小时,束腰半径对衰减率的影响较大,而当束腰半径远大于粒子半径时,接近于平面波的情况.
关键词:
广义Mie理论
轨道角动量
Laguerre-Gauss光束
单球粒子 相似文献
13.
14.
15.
16.
17.
The theory of interaction between a shaped beam and an infinite cylinder arbitrarily located in it is presented. The same approach as for the generalized Lorenz-Mie theory is first used. In particular, variable separability is assumed in solving the wave equation. The special case of Gaussian beams, however, implies that, unexpectedly, a special class of non-separable scalar potentials is required for some kinds of beams. 相似文献
18.
G. Gouesbet 《Optics Communications》2006,266(2):710-715
We consider two frameworks (i) the electromagnetic generalized Lorenz-Mie theory describing the interaction between an electromagnetic arbitrary shaped beam and a homogeneous, non-magnetic sphere, with an isotropic, linear, material and (ii) a quantum generalized Lorenz-Mie theory describing the interaction between a quantum eigen-arbitrary shaped beam and a quantum radial potential. For the time being, we restrict ourselves in this paper to elastic scattering cross-sections. We then demonstrate that a transparent macroscopic sphere in the first framework is equivalent to a superposition of two quantum-like radial potentials in the second framework. The restrictive meaning of “quantum-like” will be discussed when appropriate. 相似文献
19.
Grard Grhan Kuan Fang Ren Gerd Gouesbet Amir Naqwi Franz Durst 《Particle & Particle Systems Characterization》1994,11(1):101-106
The use of a laser sheet (or elliptical Gaussian beam) in meas-urement techniques is of growing interset. Some of these techniques take advantage of the wavefront curvature of such beams as in a dual-crylindrical wave system (DCW). Nevertheless, up to now, the analysis of the properties of the light scattered by spherical particles form the beam has been carried out largely by using geometrical optics or classical Lorenz-Mie theory. In this paper, the generalized Lorenz-Mie theory (GLMT) is applied to the analysis of an existing DCW measurement system. Differences between the results predicted by classical approaches and by GLMT are emphasized. 相似文献