Xu Tianyu, Chen Yihong, Lu Bingyu, Lai Jianjun
Appl Opt. 2024 May 20;63(15):4044-4048. doi: 10.1364/AO.517695.
We report on the design and fabrication of nearly polarization-insensitive angular filters, which have been developed through the optimization of one-dimensional / photonic crystals (PCs). We evaluate different initial systems for optimization and compare their results in terms of both the wavelength and angular selectivity. Our findings reveal that relaxing the strict periodic condition of initial photonic crystals with a small number of lattices has enabled improvement in the angular selectivity via Fabry-Perot resonances in dielectric layers, achieving a transmission as high as 81% at normal incidence by optimizing the dielectric layer thickness. The simulation results demonstrate that the transmitted beam through the angular filtering sample at 633 nm has allowable angles within 29° and 33° for TE and TM polarization, respectively, with a transmission over 80% at normal incidence. This proposed and demonstrated angular filter represents what we believe is a novel way to utilize 1D metal-dielectric PCs as polarization-insensitive angular filters, overcoming the main drawback of a low transmission. This angular filter will have significant applications in lighting, beam manipulation, optical coupling, and optical detectors.
我们报道了近偏振不敏感角滤波器的设计与制造，该滤波器是通过对一维光子晶体（PCs）进行优化而开发的。我们评估了用于优化的不同初始系统，并在波长和角度选择性方面比较了它们的结果。我们的研究结果表明，通过放宽具有少量晶格的初始光子晶体的严格周期性条件，能够通过介电层中的法布里 - 珀罗共振提高角度选择性，通过优化介电层厚度，在正入射时实现高达81%的透射率。模拟结果表明，通过角滤波样品在633nm处透射的光束，对于TE和TM偏振，允许角度分别在29°和33°以内，在正入射时透射率超过80%。这种提出并得到验证的角滤波器代表了我们认为的一种利用一维金属 - 介电光子晶体作为偏振不敏感角滤波器的新方法，克服了低透射率这一主要缺点。这种角滤波器将在照明、光束操纵、光耦合和光探测器方面有重要应用。
