Tailoring Single Plasmonic Resonance for RGB-NIR Imaging Using Nanoimprinted Complementary Plasmonic Structures of Nanohole and Nanodisk Arrays

Abstract

Plasmonic nanohole arrays (NHA) can serve as an efficient alternative for ultrathin color filters due to their high color tunability, robust stability, and simple nanofabrication. However, the periodic nanostructures inherently exhibit multiple resonances in the visible and near-infrared ranges. Here large-area and single-resonance plasmonic spectral filter for RGB-NIR imaging using nanoimprinted complementary plasmonic structures (CPS) is reported. The CPS comprise self-aligned metallic nanohole and nanodisk arrays in regular (rCPS) or inverse (iCPS) configuration, where unfavorable resonances of nanohole arrays are substantially attenuated by an extinction resonance of nanodisk arrays. The experimental results show the CPS exhibit single peaks in 437 (blue), 515 (green), 644 (red), and 912 nm (NIR), respectively. The color purity is highly increased by up to six times and thus the color reproduction range is expanded up to four times, compared to NHA. The CPS spectral filters clearly demonstrate RGB-NIR tetrachromatic imaging, resulting from the true color imaging and recognition of distinctive NIR features. This unique configuration can serve as large-scale plasmonic spectral filters that can drive multispectral or hyperspectral imaging applications.