Vis-SWIR hyperspectral microscopy imaging of plasmonic color printed arrays

This paper explores the applications of visible shortwave infrared (Vis-SWIR) hyperspectral microscopy in the context of plasmonic color printing arrays. The study focuses on metal–insulator–metal (MIM) configurations supporting gap-surface plasmons (GSPs) and investigates the spatial distribution of plasmonic resonances and the spectral response of nanostructures within the array. The fabricated plasmonic color printing samples consist of square arrays of circular gold nanodiscs (NDs) with varying diameters on top of a continuous layer of SiO₂ and gold, enabling tunable color printing. This work demonstrates the acquisition of detailed spatial and spectral information (in the spectral range from 447-1695 nm) that shows the redshifting of the absorption peak with the increasing size of plasmonic NDs and identifies the presence of fabrication errors and proximity effects in the arrays. The custom hyperspectral microscopy setup consists of a Newtec Vis-SWIR Oculus hyperspectral pushbroom camera (equipped with an IMX990 SonySWIR sensor) mounted on an Olympus microscope with a Thorlabs translation stage.