Unconventional Polarization States and Light-Matter Interaction

以非常规偏振态的光束照明与通常的教科书描述不同。非常规偏振态的两个常见例子是径向偏振和方位偏振（有时称为圆柱形矢量光束）。存在着各种各样的非常规两极分化——有些已经得到了很好的研究，而许多仍未被探索。这项研究活动汇集了三位研究人员，他们一直在研究非常规偏振态及其数学表示，偏振光的传播和聚焦，以及生物细胞内发现的小颗粒的光散射。本研究利用一种新颖的数学表示（复焦基）来模拟光学聚焦和散射，研究了径向、方位角和全庞加莱场作为复焦基的代表，以及介观粒子（包括细胞器）非常规偏振态的散射。在此过程中，我们还解决了部分相干非常规偏振态理论的制定和测试，非常规偏振态与纳米结构的耦合，并建立了相干和部分相干光传播的数值有效理论模型。我们利用最近引入的应力工程光学元件的概念，对现有的光散射显微镜进行了偏振敏感散射实验。在此过程中，我们通过引入散射分析的新分析工具，快速获取瞳孔偏振测量的新实验工具来推进光学物理，并找到更好的方法使用偏振作为改进投影成像系统的工具，如LCD投影仪和半导体光刻系统。偏振——光的矢量性质——以深刻的方式影响光的散射，因此是我们如何从散射光中获得有关散射体的信息的基础。例如，这已经在推进免疫细胞研究的细胞鉴定方面取得了良好的结果。散射在检测过程中也很重要，用于保证计算机和电子设备的半导体电路的高质量。因此，更好地理解新偏振态的物理学将对光学工程和生物医学光学等领域产生广泛的影响。每年通过本科生和研究生的参与可以看到教育的影响，他们不仅仅是作为研究助理，而且是作为鼓励独立创新的培训学生。作为光学研究所的教育工作者，我们的角色为我们提供了一个独特的平台，可以将工作成果带入硕士和学士级别的课堂，并将偏振光的令人兴奋的特性带到地区学校和科学博物馆的教育活动中。我们在光学研究所的存在为30多家公司提供技术转让，这些公司是我们工业协会计划的成员。

Illumination with beams of light in unconventional polarization states departs from the usual, textbook description. Two popular examples of unconventional polarization states are radial and azimuthal polarizations (sometimes called Cylindrical Vector Beams). A wide variety of unconventional polarizations exist -- some have been well studied, while many remain unexplored. This research activity brings together three investigators that have been studying unconventional polarization states and their mathematical representation, the propagation and focusing of polarized light, and light scattering from small particles such as those found within biological cells.This investigation makes use of a novel mathematical representation (complex-focus basis) for modeling optical focusing and scattering, the study of radial, azimuthal, and Full Poincare fields as representatives of a complex-focus basis, and the scattering of unconventional polarization states from mesoscopic particles, including cell organelles. In the process, we also address the formulation and testing of a theory of partially coherent unconventional polarization states, the coupling of unconventional polarization states to nanostructures, and develop numerically efficient theoretical models for coherent and partially coherent light propagation. We make use of the recently-introduced concept of stress- engineered optical elements to adapt an existing light scattering microscope to carry out polarization- sensitive scattering experiments. In the process, we are advancing optical physics by introducing new analytic tools for scattering analysis, a new experimental tool for rapid-acquisition pupil polarimetry, and find better ways to use polarization as a tool for improving projection imaging systems such as LCD projectors and semiconductor lithography systems.Polarization--the vector nature of light--influences the scattering of light in profound ways, and is therefore fundamental to how we gain information about a scatterer from the scattered light. This has been used to good result in advancing cell identification for immune cell research, for example. Scattering is also important in the inspection processes that are used to guarantee high quality semiconductor circuits for computers and electronic devices. A better understanding of the physics of new polarization states will therefore have a broad impact on fields such as optical engineering and biomedical optics. The educational impact is seen annually through involvement by both undergraduates and graduate students, not merely as research assistants, but as students in training who are encouraged toward independent initiatives. Our role as educators at the Institute of Optics offers us a unique platform from which to take the results of the work, bring them into the classroom at the MS and BS levels, and to take the exciting features of polarized light with us on educational activities in area schools and science museums. Our presence at the Institute of Optics offers technology transfer to over 30 companies who are members of our Industrial Associates Program.