Open AccessPartial coherence and polarization of a two-mode surface-plasmon polariton field at a metallic nanoslab
Author(s) -
Andreas Norrman,
Tero Setälä,
Ari T. Friberg
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.020696
Subject(s) - surface plasmon polariton , polarization (electrochemistry) , polariton , optics , surface plasmon , plasmon , coherence (philosophical gambling strategy) , superposition principle , physics , coherence time , electromagnetic field , materials science , coherence theory , localized surface plasmon , coherence length , condensed matter physics , laser , quantum mechanics , chemistry , superconductivity
Rigorous electromagnetic theory is utilized to characterize the partial spatial coherence and partial polarization of a two-mode field consisting of the long-range and the short-range surface-plasmon polariton at a metallic nanofilm. By employing appropriate formulations for the spectral degrees of coherence and polarization, we examine the fundamental limits for these quantities associated with such a superposition field and explore how the degrees are influenced when the media, frequency, and slab thickness are varied. It is in particular shown that coherence lengths extending from subwavelength scales up to thousands of wavelengths are possible and their physical origins are elucidated. In addition, we demonstrate that for ultra-thin films the generally highly polarized two-mode field can be partially polarized in close vicinity of the polariton excitation region. The results could benefit cross-disciplinary electro-optical applications in which near-field interactions between plasmons and nanoparticles are exploited.