Optical Control over Thermal Distributions in Topologically Trivial and Non-Trivial Plasmon Lattices

Abstract

Emergent from the discrete spatial periodicity of plasmonic arrays, surface lattice resonances (SLRs) are characterized as dispersive, high-quality polaritonic modes that can be selectively excited at specific points in their photonic band structure by plane-wave light of varying frequency, polarization, and angle of incidence. Room-temperature Bose–Einstein condensation of exciton polaritons, lasing, and nonlinear matter-wave physics have all found origins in SLR systems, but to date, little attention has been paid to their thermal behavior. Here, we combine analytical theory and numerical calculations to investigate the photothermal properties of SLRs in periodic 1D and 2D arrays of plasmonic nanoparticles coupled to each other and to the electromagnetic far-field via transverse radiation. Specifically, we demonstrate how to create steady-state SLR thermal gradients spanning from the nanoscale to hundreds of microns that are actively controllable using light in spite of heat diffusion. We also demonstrate the surprising ability to localize thermal gradients at the lattice edges in topologically non-trivial SLR dimer lattices, thereby establishing a class of extraordinary thermal responses that are unconventional in ordinary materials. This work exposes a new direction in thermoplasmonics that has only just now begun to be explored.

Chiral Lattice Resonances in 2.5-Dimensional Periodic Arrays with Achiral Unit Cells

“…17,18 Such exceptional properties have made lattice resonances the subject of an extensive research effort, which has resulted in the proposal and development of a wide range of applications. These include, among others, ultrasensitive biosensors, 19−21 color filters, 22,23 light-emitting devices, 24−28 light-to-heat transducers, 29,30 and even platforms to explore new physical phenomena. 31−36 More recently, lattice resonances have begun to be explored for applications involving chirality.…”

“…Periodic arrays of metallic nanostructures support collective electromagnetic modes commonly known as lattice resonances. − These modes, which appear in the spectrum at wavelengths commensurate with the periodicity of the array, are the result of the coherent multiple scattering between the individual constituents. , Due to their collective nature, lattice resonances give rise to very narrow optical responses, − with extraordinarily high quality factors for systems made of metallic nanostructures, − and couple strongly with light, − producing values of reflectance and absorbance that can reach the theoretical limits for two-dimensional systems. , Such exceptional properties have made lattice resonances the subject of an extensive research effort, which has resulted in the proposal and development of a wide range of applications. These include, among others, ultrasensitive biosensors, − color filters, , light-emitting devices, − light-to-heat transducers, , and even platforms to explore new physical phenomena. − …”

Chiral Optical Properties of Plasmonic Kagome Lattices

“…Therefore, for more insight, we calculated the in-plane and out-of-plane quasi-normal modes (QNMs) of the unmodified and deformed (expanded) Kagome lattices using the coupled dipole method. , In this approach, the fully retarded and frequency-dependent electric field of each LSP dipole mediates the coupling between all of the NPs in the system, leading to a nonlinear eigenvalue problem governing the QNMs. We used 12 NPs as a reducible unit cell for the calculations because this was the smallest arrangement that could account for the reduction of rotational symmetry in the lattice as the NP trimers are expanded/shrunken (Figure S12).…”

“…The quasi-normal modes of the reducible unit cells were calculated using the coupled dipole method. 44 In this approach, the complex-valued eigenfrequencies of the 12-NP reducible unit cell were determined by the condition detA ⃡ (ω r ) = 0 for the eigenvalue problem A ⃡ (ω)P(ω) = 0, where A ⃡ (ω) consists of 3 × 3 matrix blocks A ⃡ ij (ω) = α⃡ −1 (ω)δ ij − (k 2 /ε)G ⃡ ij (ω) connecting dipoles i and j. The system possesses an eigenvalue α −1 (ω r ) for complex-valued frequency ω r when |detA ⃡ (ω r )| = 0.…”

Normal Incidence Excitation of Out-of-Plane Lattice Resonances in Bipartite Arrays of Metallic Nanostructures

“…Lattice resonances appear at wavelengths that match the periodicity of the array − and, thanks to their collective nature, exhibit strong optical responses with lineshapes much narrower than those associated with the individual nanostructures composing the array. − In particular, arrays supporting lattice resonances can reach values of reflectance and absorbance that saturate the theoretical limits − , with quality factors well beyond one thousand. − At the same time, they produce very strong near-field enhancements, , only limited by the number of elements of the array that are coherently coupled . As a result of their exceptional properties, lattice resonances are being explored for the development of different optical systems such as color filters, , lenses, light-emitting devices, − and chiral elements, − as well as ultrasensitive biosensors, − light-to-heat transducers, , and even platforms to mediate long-range energy transfer, − strong coupling, , or to achieve Bose-Einstein condensation. , …”