Wang Ziyi, Zhang Rongjun, Guo Junpeng
Opt Express. 2018 Jan 8;26(1):496-504. doi: 10.1364/OE.26.000496.
A metal-dielectric subwavelength grating structure was investigated for making single-peak narrow linewidth optical reflection filters in the near-infrared region. The subwavelength grating filter structure consists of a one-dimensional periodic array of metal (gold) and dielectric (AlO) elements on a dielectric substrate. Optimized reflection filters have a single reflection peak with ~10 nm linewidth in the infrared region over a wide spectral band. Finite-difference time-domain (FDTD) simulations and multipole analysis show that the narrow linewidth reflection is due to the coupling of the Rayleigh anomaly wave to the quadrupole plasmon resonance mode of the subwavelength metal-dielectric grating. Additionally, it was found that the contrast of the indices of refraction of two dielectric materials in the subwavelength structure is critical for realizing optical filter effect.
研究了一种金属-电介质亚波长光栅结构，用于制造近红外区域的单峰窄线宽光学反射滤光片。该亚波长光栅滤光片结构由电介质衬底上的金属（金）和电介质（AlO）元素的一维周期性阵列组成。优化后的反射滤光片在宽光谱带的红外区域具有约10 nm线宽的单反射峰。时域有限差分（FDTD）模拟和多极分析表明，窄线宽反射是由于瑞利异常波与亚波长金属-电介质光栅的四极等离子体共振模式耦合所致。此外，还发现亚波长结构中两种电介质材料的折射率对比度对于实现滤光效果至关重要。
