Abstract The structural effect of subwavelength gratings as the polarizer on the polarization characteristics in visible wavelengths (400–700 nm) is systematically investigated through both numerical simulation with Finite Difference Time Doman algorithm and experiments. The grating parameters such as the material, the pitch, the duty cycle, the height and the cross-sectional shape of the grating are addressed in this work. The optimized range for those parameters is worked out, based on the desired performance margin at the level of 70% transmittance and 50:1 for the extinction ratio. Polarization performance such as the transmittance over 70% and the extinction ratio above 50:1 has been experimentally demonstrated by the 200 nm pitched grating in Al with the height of 150 nm, which was fabricated by high resolution electron beam lithography in this work, guided by the simulation result. Au grating as the polarizer was also compared but ruled out in this work because of the poor performance in polarization. This work is essential in developing grating based polarizers for polarimetric detection and imaging in visible wavelengths.

中文翻译：

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纳米结构对可见光波段金属亚波长光栅偏振器偏振特性影响的研究

摘要 通过有限差分时域算法的数值模拟和实验，系统地研究了亚波长光栅作为偏振器对可见波长（400-700 nm）偏振特性的结构影响。在这项工作中解决了光栅参数，如材料、节距、占空比、光栅的高度和横截面形状。这些参数的优化范围是根据在 70% 透射率和 50:1 消光比水平下所需的性能裕度计算出来的。高度为150 nm的Al中200 nm间距光栅已通过实验证明了偏振性能，例如透射率超过70％和消光比超过50：1，在模拟结果的指导下，在这项工作中通过高分辨率电子束光刻制造。也比较了作为偏振器的金光栅，但由于偏振性能不佳，因此在这项工作中被排除在外。这项工作对于开发基于光栅的偏振器用于可见光波长的偏振检测和成像至关重要。