Shu G, Charalampopoulos T T
Appl Opt. 2000 Nov 1;39(31):5827-33. doi: 10.1364/ao.39.005827.
The reciprocity theorem in light scattering is a general theorem that is verified theoretically and experimentally. However, violation of the reciprocity theorem has been encountered in previous investigations for simulation of light scattering from agglomerates. We demonstrate that the violations of the reciprocity theorem are due to inappropriate orientation averaging or the incorrect formulation of light-scattering quantities. In situ optical diagnostics of aggregated aerosols requires the calculation of the orientation averages of scattering quantities. Thus it is imperative to establish a criterion that can be used to determine a sufficient number of orientations for the reliable calculation of averages for the scattering quantities. It is demonstrated that the reciprocity theorem may serve as such a criterion for typical sizes of agglomerates such as flame soot with fractal dimensions D(f) = 1.8, primary particle size parameter x </= 0.3, and number of primary particles less than 260. It is shown that the use of 21 x 21 x 21 orientations will satisfy the reciprocity theorem to within 0.5%.
光散射中的互易定理是一个经过理论和实验验证的通用定理。然而，在先前对团聚体光散射模拟的研究中遇到了互易定理失效的情况。我们证明，互易定理的失效是由于取向平均不合适或光散射量的公式不正确。聚集气溶胶的原位光学诊断需要计算散射量的取向平均值。因此，必须建立一个标准，用于确定足够数量的取向，以便可靠地计算散射量的平均值。结果表明，对于典型尺寸的团聚体，如分形维数D(f)=1.8、一次粒径参数x≤0.3且一次粒子数小于260的火焰烟灰，互易定理可作为这样一个标准。结果表明，使用21×21×21个取向将使互易定理在0.5%以内得到满足。
