Surface Plasmon-Modulated Fluorescence on 2D Metallic Silver Gratings

Abstract

The emitting properties of fluorophores can be tailored by surface plasmon polaritons (SPPs), which offers the potential to understand the light-matter interactions at the nanoscale, and lays the groundwork for many future applications. As one of the useful features in SPPs-surface plasmon coupled emission (SPCE) based on the metal gratings, however, the study on its underlying modulation mechanism remains far from satisfactory. That is, how it is affected by the morphology of the grating surfaces. In this Letter, we have addressed this question in the dye-coated corrugated silver gratings, which possess different periods and depths. It is found that the properties of SPCE are strongly dependent on the dispersion relations of SPPs modulated by the grating periods.

Recent Progress on Plasmon-Enhanced Fluorescence

“…With the increase of the metal film thickness in the grating-based SPCE system, the enhanced spectra was demonstrated to be significantly affected by both depth and film thickness. Furthermore, for the short wavelength range, the higher angular sensitivity is obtained [34,35].…”

Exploration of grating-based surface plasmon resonance systems for wave vector matching to enhance plasmon modes and preliminary surface plasmon-enhanced fluorescence interrogation

“…109 Metal also allows for surface plasmon coupled emission (SPCE) which is directed, unlike the isotropic radiation from normal fluorophores. 58,63,113,116,[118][119][120][121][122] Enhanced emission due to SPCE is polarized because the radiative plasmon modes emitting the light are p-polarized. 58,113,116,122 Metal nanoparticles, 123,124 prisms with metal films 58,73 and nanostructured metal films 53,112,113,122,125,126 are typically used for MEF.…”

“…Some fluorophores can be dissolved into polymer precursors and subsequently spin coated onto grating substrates. 73,122 The optimum thickness depends on the specific fluorophore used and grating geometry. Initial exploration of grating based MEF experiments spin-coated with a thin doped polymer will be the focus of Chapter 3 of this report.…”

“…Example optical constants varying from top to bottom are shown in Additionally, emitted light from fluorophores can couple with plasmonic resonance modes through the process known as surface plasmon coupled emission (SPCE) 58,63,73,113,116,118,121,122 . Several qualities of interest exist for SPCE, included angle dependence of emission, meaning that photolumisence of fluorescent species will be enhanced at specific angles for fluorophores emitting at different wavelengths, 113,116,122 allowing for increased sensitivity for multiple fluorophores. An additional characteristic aspect includes polarization of the SPCE emitted light.…”

“…75,76,143 Degrees of grating symmetry also affect plasmonic responses, as 2D gratings excite surface plasmons (SPs) differently and can increase sensitivity. 42,79,122,144 With such a breadth of variables available for manipulation, plasmonic systems can be tuned and optimized for a variety of needs, whether the device is acting as a biosensor 19,41,54,99,101,145,146 or used to couple to molecular processes such as fluorescence emission 56,99,111,130 or vibrational modes. 36,37,40,47,49,52 Studies done on prisms with thin metal films and metallic gratings typically exploit a single plasmon mode, typically performed in reflection configuration 15,36,39 .…”