This study presents a new experiment to measure the polarization-resolved two-dimensional light-scattering patterns, near and including the backscattering direction, of fixed particles representative of some atmospheric-aerosol types. The measurements are conducted across a broad spectrum, from 450 to 850 nm, and for different polarization states. A supercontinuum laser, achromatic optics, and polarizers are used to measure the scattering patterns. Important quantities for applications such as lidar are also measured including the backscattering phase-function and the linear depolarization ratio in the exact backscattering direction. Microscopic images of the particles are provided by digital in-line holography as well. Thus, in some cases, it is possible to interpret the spectro-polarimetric measurements with knowledge of the size and shape of the particles involved. Spherical particles of known properties are used to calibrate the method. Then, Arizona test dust, Gobi and Sahara Desert dust, and ash from the Eyjafjallajökull and La Palma volcanic eruptions are studied to illustrate the method's potential for lidar applications.

中文翻译：

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大气粒子的光谱偏振反向散射


这项研究提出了一项新实验，用于测量代表某些大气气溶胶类型的固定粒子的偏振分辨二维光散射图案（靠近并包括反向散射方向）。测量在 450 至 850 nm 的宽光谱范围内针对不同的偏振态进行。使用超连续谱激光器、消色差光学器件和偏振器来测量散射图案。还测量了激光雷达等应用的重要量，包括反向散射相位函数和精确反向散射方向上的线性去偏振比。颗粒的显微图像也由数字在线全息术提供。因此，在某些情况下，可以通过了解所涉及颗粒的尺寸和形状来解释分光偏振测量。使用已知特性的球形颗粒来校准该方法。然后，研究了亚利桑那州的测试灰尘、戈壁和撒哈拉沙漠的灰尘以及埃亚菲亚德拉冰盖和拉帕尔马火山喷发的灰烬，以说明该方法在激光雷达应用中的潜力。