Li Yiyang, van de Groep Jorik, Talin A Alec, Brongersma Mark L
Sandia National Laboratories , Livermore , California 94550 , United States.
Department of Materials Science and Engineering , Stanford University , Stanford , California 94305 , United States.
Nano Lett. 2019 Nov 13;19(11):7988-7995. doi: 10.1021/acs.nanolett.9b03143. Epub 2019 Oct 4.
Plasmonic antennas and metasurfaces can effectively control light-matter interactions, and this facilitates a deterministic design of optical materials properties, including structural color. However, these optical properties are generally fixed after synthesis and fabrication, while many modern-day optics applications require active, low-power, and nonvolatile tuning. These needs have spurred broad research activities aimed at identifying materials and resonant structures capable of achieving large, dynamic changes in optical properties, especially in the challenging visible spectral range. In this work, we demonstrate dynamic tuning of polarization-dependent gap plasmon resonators that contain the electrochromic oxide WO. Its refractive index in the visible changes continuously from = 2.1 to 1.9 upon electrochemical lithium insertion and removal in a solid-state device. By incorporating WO into a gap plasmon resonator, the resonant wavelength can be shifted continuously and reversibly by up to 58 nm with less than 2 V electrochemical bias voltage. The resonator can remain in a tuned state for tens of minutes under open circuit conditions.
等离子体天线和超表面可以有效地控制光与物质的相互作用，这有助于对包括结构色在内的光学材料特性进行确定性设计。然而，这些光学特性在合成和制造后通常是固定的，而许多现代光学应用需要主动、低功耗和非易失性调谐。这些需求推动了广泛的研究活动，旨在识别能够在光学特性上实现大的动态变化的材料和共振结构，特别是在具有挑战性的可见光谱范围内。在这项工作中，我们展示了包含电致变色氧化物WO的偏振相关间隙等离子体谐振器的动态调谐。在固态器件中进行电化学锂插入和去除时，其在可见光中的折射率从n = 2.1连续变化到1.9。通过将WO纳入间隙等离子体谐振器，在小于2 V的电化学偏置电压下，谐振波长可以连续且可逆地移动多达58 nm。在开路条件下，谐振器可以在调谐状态下保持数十分钟。
