UV-Polarizers for wavelengths from 150 to 250 nm based on exciton generation in dielectric materials (PolEx)

真空紫外线(VUV)光谱范围在光学成像和分析应用中起着重要作用，例如光刻、光谱分析和椭偏测量。因此，光的偏振控制可以增强成像质量，并提供关于材料性质的有价值的信息，甚至可以精确到原子尺度。紧凑型、可积式光学偏振器具有大面积的可扩展性和对不对准的稳健性，将有力地促进VUV仪器小型化的发展。例如，这种设备在卫星遥感中可能会引起人们的兴趣。传统的金属线栅偏振器通常用于可见光和红外光谱范围。然而，它们在波长小于250纳米时越来越失效，因此在真空紫外光中也是如此。在这个项目中，我们的目标是将这种纳米光学偏振器的应用极限降低到150 nm。为此，我们提出并研制了基于人工介质中激子产生的光栅偏振器。为了设计这些元件，光谱定制的带隙材料将是非常有利的。除了材料方面的基础研究外，研究的重点将是开发新型的分段光栅结构。通过分割，我们的目标是实现具有前所未有的多光谱功能的偏振器。该项目中实验实现的元素有望提供到目前为止仅适用于可见光和红外光谱区域的线栅偏振器的性能。由于它们的宽带特性和对不对准的稳健性，它们将在紧凑型真空紫外椭偏仪和偏振分辨成像系统中发挥很大的作用。

The vacuum ultraviolet (VUV) spectral range plays a major role in optical imaging and analytical applications such as lithography, spectroscopy and ellipsometry. Thereby, the polarization control of light enables enhanced imaging quality and provides valuable information about material properties down to atomic scale. Compact, integrable optical polarizers with scalability to large areas and robustness towards misalignment would strongly promote advances to miniaturized VUV instruments. For instance, such devices can be of interest in satellite remote sensing. Conventional metal wire grid polarizers are commonly used in the visible and infrared spectral range. However, they increasingly fail at wavelengths smaller than 250 nm and thus also in the VUV. In this project we aim to drive the application limits of such nano-optical polarizers down to 150 nm. For this purpose, we propose and develop grating polarizers based on the generation of excitons in artificial dielectric media. In order to design these elements, spectrally tailored bandgap materials will be of great advantage. Beside fundamental studies on materials the research focus will be the development of novel segmented grating structures. By segmentation we aim for the realization of polarizers with unprecedented multi-spectral function. The elements experimentally realized in this project are expected to provide a performance up to now exclusively available for wire grid polarizers in the VIS and IR spectral region. Due to their broadband behavior und robustness towards misalignment they will be of high benefit in compact VUV ellipsometers and polarization resolved imaging systems.