Collective plasmonic modes excited in Al nanocylinder arrays in the UV spectral region.

A periodic array of plasmonic nanocylinders can sustain both surface plasmon polaritons (SPPs) and optical diffraction in the plane of the array. Thus the optical energy can be efficiently trapped in the plane of the array, providing a good platform for controlling light. Plasmonic arrays have been investigated in the visible range, while studies in the ultraviolet (UV) range have been limited due to material-related restrictions and higher precision required for optical diffraction in the UV compared to that in the visible range. In this study, we fabricated periodic arrays of Al nanocylinders with periods comparable to optical wavelengths in the UV for simultaneous excitation of both SPPs and optical diffraction in the UV spectral region. We deposited UV-absorbing and highly luminous dielectric films on the arrays, observed enhanced photoluminescence of the film under UV laser excitation, and demonstrated that such periodic arrays can trap the UV light energy. Our findings show that periodic arrays of Al nanocylinders are useful for controlling UV light.