McClain W M, Jeng W H, Pati B, Shi Y, Tian D
Appl Opt. 1994 Mar 1;33(7):1230-41. doi: 10.1364/AO.33.001230.
A two-frequency beam from a Zeeman laser scatters elastically from an isotropic medium, such as randomly oriented viruses or other particles suspended in water. The Zeeman effect splits the laser line by 250 kHz, and beats can be seen electronically in the signal from a phototube that views the scattered light. There are independently rotatable half-wave and quarter-wave retardation plates in the incident beam and a similar pair in the observed scattered beam, plus a fixed linear polarizer directly in front of the detector. Each of the four retarders has two angular positions, providing a total of 16 possible polarization cases. For each of the 16 cases, there are three data to be collected: (1) the average total intensity of the scattered light, (2) the amplitude of the beats in the scattered light, and (3) the phase shift between the beats of the scattered light and those of a reference signal from the laser. When a singular value decomposition technique is used, these threefold redundant data are rapidly ransformed into a best-fit 4 × 4 Mueller scattering matrix. We discuss several different measurement strategies and their systematic and statistical errors. We present experimental results for two kinds of particle of wavelength size: polystyrene spheres and tobacco mosaic virus. In both cases the achiral retardation element M(34) of the Mueller matrix is easily measurable.
来自塞曼激光器的双频光束从各向同性介质（如随机取向的病毒或悬浮在水中的其他颗粒）上发生弹性散射。塞曼效应使激光谱线分裂250千赫，在观察散射光的光电管信号中可以通过电子方式看到拍频。在入射光束中有可独立旋转的半波和四分之一波延迟板，在观察到的散射光束中也有类似的一对，另外在探测器正前方有一个固定的线性偏振器。四个延迟器中的每一个都有两个角位置，总共提供16种可能的偏振情况。对于这16种情况中的每一种，都有三个数据要采集：（1）散射光的平均总强度，（2）散射光中拍频的幅度，以及（3）散射光的拍频与来自激光器的参考信号的拍频之间的相移。当使用奇异值分解技术时，这些三重冗余数据会迅速变换为一个最佳拟合的4×4穆勒散射矩阵。我们讨论了几种不同的测量策略及其系统误差和统计误差。我们给出了两种波长尺寸颗粒（聚苯乙烯球体和烟草花叶病毒）的实验结果。在这两种情况下，穆勒矩阵的非手性延迟元素M(34)都很容易测量。
