A broadband air gap polarization prism design based on Hg2Cl2, Hg2Br2, and Hg2I2 crystals is suggested. Spectral ranges of operation extend from visible light up to 40 μm, and strong birefringence of the materials makes it possible to optimize the crystal cut geometry. Results include a large symmetric field of view up to 20 deg wide within the entire mid- and far-infrared transparency range, as well as a power transmittance of more than 80%. The transmittance is determined by the Fresnel reflection at the entrance and exit windows. Furthermore, it can be improved by optional antireflection coatings; losses in the air gap do not exceed 1%. Due to a combination of useful properties, the suggested design significantly outperforms commonly available crystal polarizers.

中文翻译：

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基于卤化汞晶体的宽带格兰型极化方案

建议基于Hg2Cl2，Hg2Br2和Hg2I2晶体的宽带气隙偏振棱镜设计。操作的光谱范围从可见光扩展到40μm，并且材料的强双折射使优化晶体切割的几何形状成为可能。结果包括在整个中红外和远红外透明范围内的最大对称视场，宽达20度，并且功率透射率超过80％。透射率由入射窗和出射窗处的菲涅耳反射决定。此外，可以通过可选的抗反射涂层来改善它；气隙的损失不超过1％。由于多种有用特性的组合，建议的设计大大优于通常使用的晶体偏振器。