Experimental observation of narrow surface plasmon resonances in gold nanoparticle arrays

Abstract

We demonstrate that coupling between grating diffraction and localized surface plasmons in two-dimensional gold nanoparticle arrays in water leads to narrow near-infrared resonance peaks in measured far field extinction spectra. Good agreement is obtained between finite difference time domain ͑FDTD͒ calculations and experimental extinction spectra. The FDTD calculations predict that the gold nanoparticle arrays exhibit near-field electric field intensity ͑E 2 ͒ enhancements approximately one order of magnitude greater than those of single isolated gold nanoparticles.

Surface modes in plasmonic crystals induced by diffractive coupling of nanoantennas

“…In this case, diffractive coupling due to the scattering of light by the array produces narrow extinction resonances, which have been demonstrated experimentally very recently. [12][13][14][15] Such resonances exhibited by arrays of nanoantennas are a signature of the excitation of lattice surface modes extending in the plane of the array. This Rapid Communication investigates the characteristic lengths of lattice surface modes on plasmonic crystals of nanoantennas.…”

“…An efficient diffractive coupling between nanoantennas is obtained when the array is embedded in a homogeneous dielectric environment. [13][14][15] Therefore, we put an amorphous quartz upperstrate on top of the antenna array. Good optical contact between substrate and upperstrate was obtained with a thin layer of refractive index matching liquid.…”

Diffractive arrays of gold nanoparticles near an interface: Critical role of the substrate

“…Recent advances in the control of the angular emission from quantum dots are also based on diffractive coupling of antenna elements. 19 Two-dimensional arrays of nanoantennas can be produced with good fabrication control by techniques such as electronbeam lithography, [8][9][10][11]20 contact printing, 12 and colloidal chemistry. 21 These samples are most commonly manufactured on a substrate of high refractive index compared to the upper medium ͑typically air or water for biosensing applications͒.…”

“…[1][2][3] The subject has recently received renewed attention 4,5 with the prediction 6,7 and experimental observation [8][9][10][11][12] of interesting optical phenomena that result from the interaction between the geometrical resonance associated with light diffraction and the excitation of localized surface-plasmon resonances in metallic nanoparticles, which play the role of plasmonic nanoantennas. 13 In addition to the interesting physics revealed in such systems, a number of applications have been proposed, including nanoscale energy transport, 14,15 sensing, 16,17 and modifying spontaneous emission, 18 which rely on the improved quality factor resulting from the reduction in radiative damping of the array as compared to localized plasmons excited in isolated particles.…”

Spectrally selective chiral silicon metasurfaces based on infrared Fano resonances

“…A notable exception is the special class of diffraction-coupled plasmonic arrays 25,[43][44][45] , which rely on the geometric resonance that arises when the wavelength of light is commensurate with the array's periodicity 44 . Such plasmonic arrays can possess a very high Q-factor, but suffer from the same limitations as GRM-based photonic crystals, affecting a number of important applications that involve ultrasmall (several wavelengths in size) samples.…”