Imaging of dynamic heterogeneities in multiple-scattering media
Imaging of dynamic heterogeneities in multiple-scattering media
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DOI：
10.1364/josaa.14.000185
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发表时间：
1997-01-01
影响因子：
1.9
通讯作者：
Maynard, R
中科院分区：
文献类型：
--
作者：
Heckmeier, M;Skipetrov, SE;Maynard, R
提出了一种可视化物体的新方法，该物体具有嵌入液体多重散射介质中的成分散射粒子的不同内部动态。我们报告动态多重光散射实验和理论模型，基于扩散光子密度波的浓缩胶体悬浮液中的布朗运动，作为一个背景介质，其中插入一个毛细管包含（i）相同的悬浮液下流动，或（ii）悬浮液中的布朗运动的不同粒径。这些模型对象，具有纯动态的，但没有静态的散射对比度，可以通过空间分辨测量的时间自相关函数g（2）（τ）的散射光强度在样品表面可视化。最大对比度发生在参数依赖的有限相关时间τ。这种效应的物理起源概述我们的数据是在良好的定量协议与模型，没有可调参数。(C)1997年，美国光学学会。
A new method of visualizing objects with distinct internal dynamics of the constituent scattering particles embedded in a liquid multiple-scattering medium is presented. We report dynamic multiple-light-scattering experiments and a theoretical model, based on diffusing photon-density waves for concentrated colloidal suspensions in Brownian motion, as a background medium into which is inserted a capillary containing (i) the same suspension under flow, or (ii) suspensions of different particle sizes in Brownian motion. These model objects, with purely dynamic but no static scattering contrast, can be visualized by space-resolved measurements of the time autocorrelation function g(2)(tau) of the scattered light intensity at the sample surface. Maximum contrast occurs at a parameter-dependent finite correlation time tau. The physical origin of this effect is-outlined Our data are in excellent quantitative agreement with the model, with no adjustable parameter. (C) 1997 Optical Society of America.