Excitation of confined modes on particle arrays

Abstract

We describe both theoretically and experimentally the existence and excitation of confined modes in planar arrays of gold nanodisks. Ordered 2D lattices of monodispersive nanoparticles are manufactured, embedded in a silica matrix, and exposed to evanescent prism-coupling illumination, leading to dark features in the reflectivity, which signal the presence of confined modes guided along the arrays. We find remarkable agreement between theory and experiment in the frequency-momentum dispersion of the resonances. Direct excitation of these modes reveals long propagation distances and deep extinction features. This combined experimental and theoretical characterization of guidedmodes shows a good understanding of the optical response of metallic particles arrays, which can be beneficial in future designs of optical-signal and distant-sensing applications. © 2013 Optical Society of America. ; This work has been supported in part by the European Union (NMP4-2006-016881-SPANS, NMP4-SL-2008-213669-ENSEMBLE,FP7-ICT-2009-4-248909-LIMA, and FP7-ICT-2009-4-248855-N4E), the Spanish MEC (MAT2010-14885 and Consolider Nano-Light.es), and the research program of the Foundation for Fundamental Research on Matter (FOM), which is financially supported by the Netherlands Organization for Fundamental Research (NWO) and is part of an industrial partnership program between Philips and FOM. It is also supported in part by NanoNextNL, a micro and nanotechnology consortium of the Government of the Netherlands and 130 partners. X.M.B. acknowledges a Spanish CSIC-JAE grant. ; Peer Reviewed