Enhanced Fields in Mirror-Backed Low-Index Dielectric Structures

作者：Xianyu Ao, Danqing Wang, Teri W. Odom · 发表于：ACS Photonics · 年份：2019 · DOI：10.1021/acsphotonics.9b00931 · 被引用次数：28 · 研究领域：Plasmonic and Surface Plasmon Research、Near-Field Optical Microscopy、Photonic Crystals and Applications

This Letter reports the localization of optical fields in dielectric nanopillar arrays on a metal film. Large-area arrays of tall (>450 nm) polymer pillars were patterned on an optically thick gold film by solvent-assisted nanoscale embossing. This hybrid dielectric–metal system supports two high-quality band-edge modes, with the mode at the wavelength closest to the array spacing concentrating electromagnetic field intensity at the tops of and extending beyond the nanopillars. Organic dye molecules mixed in the polymer matrix of the nanopillars showed enhanced radiative emission rates and narrow-band and unidirectional fluorescence emission. This hybrid platform offers prospects for strong near-field enhancements from low-index dielectric nanostructures.