High-Performance Electro-Optic Manipulation by Plasmonic Light Absorber With Nano-Cavity Field Confinement

Abstract

：Narrowband light absorber with multi-band plasmonic resonances is numerically investigated for high-performance electrical manipulation via introducing the electro-optic (EO) medium in the slit array based grating structure. A maximal absorption efficiency of 99.5% is achieved. The spectral shift sensitivity reaches 0.99 nm/V. Besides, the large spectral intensity change is also obtained due to the use of sharp resonances, which therefore ensures the high signal-to-noise ratio for the manipulation process. It is observed that the strong surface plasmon resonance and the localized optical cavity modes can introduce the differential responses for the multiple modes under the optical adjusting process and also for the EO manipulation process. These features not only contribute to produce the new EO modulator platforms based on the light absorbers but also pave new ways for the cavity-enhanced high-performance EO operation. Moreover, the absorption properties can be well maintained in a wide range of the structural parameters, indicating the high tolerance of the fabrication process. The findings can pave new insights into the high-performance manipulations via the narrowband absorbers with strong electromagnetic field enhancement and hold wide applications in dynamic switching, filtering, displaying, etc.