Limit possible electric field in plasmon nanogap resonator

2021/11/10 by Sarychev, Andrey K., Ivanov, Andrey V., Barbillon, Grégory
#FOS: Physical sciences #Optics (physics.optics)

paper · doi:10.48550/arxiv.2111.05511

Abstract

We propose the theory of the plasmon excited in ultra-narrow plasmonic gap formed by a metal cylinder on a metal surface, that generates a huge resonant local electromagnetic field in optical frequencies. Resonance conditions are found. The maximum possible enhancement of the electric field in the nanogap is estimated as |E_max |/ | E₀ | ∝ | ε_m |³ ε_d^-1 ( \Im ε_m) ^-2 A simple ultranarrow-gaped resonator can be used for SERS sensing and infrared spectroscopy of adsorbed molecules. We assume that a plasmonic nanogap is simplest and most straightforward way to increase flexibility as well as sensitivity of the plasmon-enhanced spectroscopes.

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