Department of Electronic Engineering, Kwangwoon University, 20 Kwangwoon-ro, Nowon-Gu, Seoul 01897, South Korea.
School of Physics, The University of Melbourne, Melbourne, Victoria 3010, Australia.
Sci Rep. 2017 Jan 9;7:40073. doi: 10.1038/srep40073.
Highly efficient polarization-tuned structural color filters, which are based on a one- dimensional resonant aluminum grating that is integrated with a silicon nitride waveguide, are proposed and demonstrated to feature a broad color palette. For such a metallic grating structure, transmissive color filtering is only feasible for the incident transverse-magnetic (TM) polarization due to its high reflection regarding the transverse-electric (TE) case; however, polarization-tuned customized colors can be efficiently achieved by optimizing the structural parameters like the duty ratio of the metallic grating. For the fabricated color filters, the transmission peaks, which are imputed to the resonance between the incident light and the guided modes that are supported by the dielectric waveguide, provided efficiencies as high as 90% and 70% for the TM and TE polarizations, respectively, as intended. Through the tailoring of the polarization, a group of filters with different grating periods were successfully exploited to produce a broad color palette spanning the entire visible band. Lastly, a nanoscale alphabetic pattern featuring a flexible combination of colorations was practically constructed via an arrangement of horizontal and vertical gratings.
提出并演示了一种基于集成氮化硅波导的一维共振铝光栅的高效偏振调谐结构色滤波器，其具有广泛的颜色选择。对于这种金属光栅结构，由于其对横电（TE）情况的高反射率，仅对横向磁（TM）偏振的光进行透射颜色过滤才是可行的；然而，通过优化金属光栅的占空比等结构参数，可以有效地实现偏振调谐的定制颜色。对于所制造的颜色滤波器，由于导模与入射光之间的共振，传输峰值分别高达 90%和 70%，这归因于介电波导的支持，这分别对应于 TM 和 TE 偏振。通过偏振的调整，成功地利用一组具有不同光栅周期的滤波器来产生跨越整个可见波段的广泛颜色选择。最后，通过水平和垂直光栅的排列，实际构建了具有灵活组合的颜色的纳米字母图案。
