Specific features of depolarized and polarized light scattering in a solution with a layering isolated region

Intensities of depolarized and polarized light scattering in guaiacol-glycerin solutions with layering isolated regions are measured. It is shown that (a) the depolarized scattering intensity is the same above the higher critical point (HCP) and below the lower critical point (LCP), and (b) the polarized scattering intensity below LCP is higher, the higher the HCP. An empirical formula is offered to describe the polarized scattered light intensity. No increase in the single depolarized scattering intensity is found approaching LCP and HCP.     

光子晶体光纤中去极化型声波导布里渊散射频移和散射效率研究

利用矢量有限元法,数值模拟了不同结构参数下光子晶体光纤中空气孔填充率与去极化型声波导布里渊散射频移的关系,以及布里渊散射频移与布里渊散射效率的关系。研究结果表明,空气孔填充率的增大会导致扭转径向模式的去极化型声波导布里渊散射频移下移。空气孔节距或纤芯直径一定时,高阶模式的频移对空气孔填充率的变化更为敏感。扭转径向模式的去极化型布里渊散射效率都随布里渊散射频移的增大而增大。     

The spectrum of depolarized light scattered from critical mixtures

The temperature dependence of the spectrum of depolarized light scattering in a uniform phase of critical mixtures of n-dodecane-ββ' dichlorodiethyl ether and n-hexane-nitrobenzene is studied experimentally. The depolarized light scattering spectrum was found to narrow dozens of times in the temperature interval from 30 to 1°C from the critical temperature of exfoliation in both mixtures. The results obtained are discussed.     

A Depolarized Dynamic Light Scattering Method to Calculate Translational and Rotational Diffusion Coefficients of Nanorods

A new analysis of depolarized dynamic light scattering data is presented, which allows the unambiguous determination of rotational and translational diffusions coefficients of nanorods in suspension. By visualizing data scaling, purely translational diffusive motions can be isolated from vertically polarized scattering, allowing the unique determination of rotational diffusion from the depolarized scattering. The method is applied to nanorods with four different aspect ratios, and compared with theoretical predictions. Diffusion coefficients obtained show good agreement with calculations based on the direct measurements of rod length and diameter. Where the theories are shown to be valid, the method allows the measurement of statistically meaningful particle sizes and aspect ratios.     

Polarized Raman Scattering in Silicon Layers on Sapphire

The intensities of polarized components of Raman light scattering are measured for different crystallographic directions in epitaxial layers of silicon on sapphire. The experiment shows that the scattered radiation has a strong depolarized component, which is directly related to the occurrence of defects in the epitaxial layer. A model of an ensemble of crystallites is proposed to describe a defect crystal silicon layer on sapphire. It is shown that the characteristic value of disordering of crystalline domains in the epitaxial layer can be determined from the ratio between the intensities of the polarized and depolarized components. From measurements of the Raman scattering intensity as a function of the crystallographic direction, the anisotropy of the Raman scattering tensor is determined. Numerical values for two samples are obtained.     

GaAs/AlAs超晶格的近共振喇曼散射研究

本文介绍GaAs/AlAs超晶格的室温近共振喇曼散射测量结果。由于超晶格中Fr?hlich相互作用的共振增强效应,GaAs LO声子偶模的散射得到了很大的增强。和前人的结果一样,在偏振谱我们观察到了偶模。但和前人的结果不同,在退偏振谱中我们观察到的是奇模,而不是偶模。从而证明了在近共振条件下LO声子限制模仍遵从与非共振时一样的选择定则。二级喇曼散射实验结果表明,在偏振谱中二级谱是由两个偶模组合而成,而在退偏振谱中的二级谱与前人的结果不同,由一个奇模与一个偶模组合而成。上述结果与最近提出的黄朱模型的预言是一 关键词：     

透射光偏振度与散射次数关系的研究

偏振态与散射次数的关系对于提取深入组织内部的后向散射光有很重要的价值.本文分析了透射光的偏振度与光在介质中的散射次数的关系,给出了偏振光完全失去偏振态所需的散射次数,并用直接散射的实验方法进行了验证,得出当散射次数为14次时偏振光将失去其偏振特性的结论.     

Effect of the network on the director fluctuations in a nematic side-group elastomer analysed by static and dynamic light scattering

The European Physical Journal E - Static and dynamic light scattering experiments were performed on monodomains of a crosslinked nematic side-group polysiloxane. The depolarized scattering caused...     

The effect of diatom-diatom collisions on depolarized light scattering linewidths : I. General theory

With the use of an appropriately generalized Waldmann-Snider collision (super-) operator, a unified kinetic theory treatment of depolarized light scattering (both depolarized Rayleigh and rotational Raman) and their related linewidths is presented for gases of rigid rotor molecules. Explicit expressions are given, both exactly and within a distorted wave Born approximation, for the various state-to-state (i.e. rotational quantum number dependent) collision processes which can contribute to any observed linewidths due to diatom-diatom collisions. The results of this paper are employed in the calculation of the depolarized linewidths for the hydrogen isotopes in the following article.     

光在大分子聚合物中的解偏和散射

文章报道了光在大分子聚合物中的前向散射和解偏现象,并用Mie散射和Fraunhofe衍射理论对其进行了解释,提出了小角度散射的光解偏理论。     

Spectral measurements of the depolarized multiple scattered light from a binary mixture near its critical point

We report the first spectral measurements of the depolarized multiple scattered light from a binary mixture near its critical point. Spectral analysis of the depolarized light allows to separate rigorously the multiple scattering from the light scattered by the anisotropy fluctuations. The results are in very good agreement with a recent theory by Oxtoby-Gelbart.     

Diffusion Collisionnelle Induite Pour Les Bandes Rayleigh Et ν1 Raman Du Liquide Isotopique CCl4

We have studied the depolarized component of the ν₁ Raman band of the isotopic liquid C³⁵Cl₄ at 296 K. We compare the experimental Rayleigh and Raman depolarized scattering with theoretical spectra calculated using dipole induced dipole approximation.     

Surface-induced smectic-ordering effect in thin nematic liquid-crystal cell

The European Physical Journal E - Collective rotational motion in nondilute isotropic solutions of semirigid chains is sensitively probed by depolarized light scattering over a broad time range....     

The temperature dependence of the Rayleigh line wing and depolarized combinational scattering line widths in critical mixtures

It has been experimentally found that at approaching the critical temperature of the exfoliating mixture carbon-disulfide-ethanol the widths of the Rayleigh line wing and the depolarized combinational scattering line drastically decrease. The same phenomenon was observed for 3 nitrobenzene combinational line scattering in a nitrobenzene—n-hexane mixture.     

Depolarized light scattering from interacting brownian spheres

The initial decay time of the spectrum and the integrated intensity of depolarized light scattered from a system of interacting spherical and optically isotropic colloidal particles as a function of scattering angle is calculated in the double scattering approximation. These quantities can be reduced in the short-time regime to the static structure factor of single scattering, as observed in polarized scattering for systems of intermediate concentrations of colloidal particles. The results are applied to charged polysterene spheres in solutions and it is shown by numerical calculations that the presence of interactions can modify the angular dependence of initial decay time and integrated intensity considerably.     

海面的激光散射特性

 基于随机面元模型，建立了海面对激光散射的理论模型，详细分析了海面散射的退偏振特性。理论分析表明：除后向外其它方向的散射光都存在部分退偏振现象；但是浮于海面上或悬浮于海面的物体表面对激光散射所具有的退偏振特性明显不同于海面散射的退偏振特性。因此可以根据这些差异来遥感海面的漂浮或悬浮物体，该结论已经被实验证实。     

Depolarized light scattering from simple fluids

It is shown that even in single scattering approximation, the light scattered by a simple fluid exhibits a depolarized component which arises from including additional terms in the current density. A new way of measuring the shear viscosity of a fluid is proposed.     

Anomalous density dependence in depolarized light scattering by simple fluids

An abrupt and possibly discontinuous change in the depolarized light scattering spectrum of fluid xenon with increasing density is reported. An approximate location of this anomaly in the phase diagram is given. The significance of the experimental observation in connection with equilibrium properties of the fluid is discussed.     

Cross-polarized backscatter in optical coherence tomography of biological tissue

We have observed that cross-polarized backscatter measured by optical coherence tomography of human skin in vivo is surprisingly strong. We identify and give evidence of its main origins: single scattering from nonspherical particles and multiple scattering by particles with sizes much larger than a wavelength. Our findings show that depolarized light scattered by dense large-diameter particles maintains a high degree of temporal coherence and that differential-polarization imaging improves contrast between particles of different sizes.