Feng Aosong, Yu Zejie, Sun Xiankai
Opt Express. 2018 Oct 29;26(22):28197-28205. doi: 10.1364/OE.26.028197.
Nanostructured plasmonic metamaterials are an excellent platform for narrowband optical absorption, which has wide applications in sensing, filtering, modulation, and emission tailoring. However, achieving a subnanometer absorption bandwidth for optical sensing and dynamical control of light is still challenging. Here, we propose an asymmetric metagrating structure and make use of the propagating surface plasmonic mode that has a small dissipation rate, to achieve perfect optical absorption with a bandwidth of 0.28 nm near the wavelength of 1.55 μm. Our proposed structure can be used in solution environments as a chemical or biological sensor in the visible spectral range just by changing the structural parameters. The sensor possesses a sensitivity of 440 nm/RIU and figure of merit of 1333.33 RIU. In addition, by combining an organic electro-optic material with this metagrating, our device can be reconfigurable with a dynamic range of 15.52 dB. Therefore, our proposed metagrating platform not only works as an ultranarrow-band absorber, but also can be employed for optical sensing and dynamic control of light.
纳米结构的等离子体超材料是实现窄带光吸收的优良平台，在传感、滤波、调制和发射定制等方面有着广泛应用。然而，实现用于光学传感和光动态控制的亚纳米吸收带宽仍然具有挑战性。在此，我们提出一种不对称超光栅结构，并利用具有小耗散率的传播表面等离子体模式，在1.55μm波长附近实现了带宽为0.28nm的完美光吸收。我们提出的结构只需改变结构参数，就能在溶液环境中用作可见光谱范围内的化学或生物传感器。该传感器的灵敏度为440nm/RIU，品质因数为1333.33RIU。此外，通过将有机电光材料与这种超光栅相结合，我们的器件可实现动态范围为15.52dB的可重构性。因此，我们提出的超光栅平台不仅可作为超窄带吸收器，还可用于光学传感和光的动态控制。
