Asymmetric Scattering and Reciprocity in a Plasmonic Dimer

Abstract

We study the scattering of polarized light by two equal corner stacked Au nanorods that exhibit strong electromagnetic coupling. In the far field, this plasmonic dimer manifests very prominent asymmetric scattering in the transverse direction. Calculations based on a system of two coupled oscillators, as well as simulations based on the boundary element method, show that, while in one configuration both vertical and horizontal polarization states are scattered to the detector, when we interchange the source and the detector, the scattered intensity of the horizontal polarization drops to zero. Following Perrin’s criterion, it can be shown that this system, as well as any other linear system not involving magneto-optical effects, obeys the optical reciprocity principle. We show that the optical response of the plasmonic dimer, while preserving electromagnetic reciprocity, can be used for the non-reciprocal transfer of signals at a subwavelength scale.

Sixteen Pairs of 4-Component Spinors for SL(4,C) and Four Types of Transformations with a Conjugate Space Which Has No Counterpart in SL(2,C)

“…There are coherent parallel combination experiments that demonstrate the state interpretation of J, N and |h in light-nanoparticle interactions [18][19][20][21]. In a certain interval of wavelength, a nanorod oriented at an angle θ in the the x-y plane responds to the incident light propagating along the z axis as a linear polaizer and the associated vector state is…”

“…From Equation (205), γ = −π/2 and from Equation (207) Ω/2 = π/2. Hence, γ = −Ω/2 21 . Similar relations can be derived with Z matrices and 4-component spinor pairs.…”

“…Sign depends on the sense of the cyclic path 20. Geometric phase can also be defined and calculated for an open loop operations on the Poincare sphere 21. Negative sign is due to the CCW cyclic path.Preprints(www.preprints.org) | NOT PEER-REVIEWED | Posted: 25 September 2023 doi:10.20944/preprints202303.0540.v3…”

“…Lorentzian polarizability and the interaction coefficient are functions of the wavelength of the incident light, hence the phenomenon of plasmonic hybridization occurs at wavelengths that make the denominator of g zero 31. Optical activity can be observed even in a planar geometry in sideways scattering directions[21].Preprints(www.preprints.org) | NOT PEER-REVIEWED | Posted: 25 September 2023 doi:10.20944/preprints202303.0540.v3…”