Programmable and reversible plasmon mode engineering

Abstract

Plasmonic nanostructures with enhanced localized optical fields as well as narrow linewidths have driven advances in numerous applications. However, the active engineering of ultranarrow resonances across the visible regime-and within a single system-has not yet been demonstrated. This paper describes how aluminum nanoparticle arrays embedded in an elastomeric slab may exhibit high-quality resonances with linewidths as narrow as 3 nm at wavelengths not accessible by conventional plasmonic materials. We exploited stretching to improve and tune simultaneously the optical response of as-fabricated nanoparticle arrays by shifting the diffraction mode relative to single-particle dipolar or quadrupolar resonances. This dynamic modulation of particle-particle spacing enabled either dipolar or quadrupolar lattice modes to be selectively accessed and individually optimized. Programmable plasmon modes offer a robust way to achieve real-time tunable materials for plasmon-enhanced molecular sensing and plasmonic nanolasers and opens new possibilities for integrating with flexible electronics.plasmonics | nanoparticles | lattice plasmons | mode engineering | flexible substrates S ingle plasmonic nanoparticles exhibit wide resonant linewidths that can be narrowed by diffractive coupling with neighboring particles (1-3) or nanoscale coupling to metal films (4). The integration of plasmonic nanoparticles on top of elastomeric substrates has enabled tuning of the plasmon modes (5-10), but the resonances remain broad because of radiative damping. Although long-range coupling in periodic arrays can result in extremely narrow resonances (full width at half maximum (FWHM) linewidths <5 nm) (11-13), the design criteria for these lattice plasmon modes are stringent, and the quality of the arrays is fixed at the time of fabrication. Here we report a platform that can selectively access and engineer the quality of distinct, broadband plasmon modes over the entire visible spectrum. Aluminum nanoparticle arrays embedded in an elastomeric slab exhibited high-quality resonances (FWHM: 3-7 nm) at wavelengths not possible for gold or silver and that could be continuously tailored over a large wavelength range (>100 nm). We exploited mechanical stretching to improve and tune simultaneously the optical response of asfabricated arrays by shifting the diffraction mode relative to the single-particle dipolar or quadrupolar resonances. Moreover, dipolar and quadrupolar lattice modes could be individually optimized by stretching along different array directions. The ability to realize programmable plasmon modes from a single system enables tunable substrates for fluorescence enhancement, photocatalysis, biosensing, nanolasers, as well as printed color pixels (14-21).Results Fig. 1 summarizes a platform that can achieve continuously tunable, high-quality lattice plasmon modes based on hexagonal arrays of aluminum nanoparticles embedded in an elastomeric slab. Aluminum nanostructures can support plasmon resonances spanning from the UV to near-IR becau...

Mechanotunable Plasmonic Properties of Colloidal Assemblies

“…Both conditions can be overcome by utilizing SLRs instead of LSPRs for creating an optical feedback. The combination of elastomeric substrates and lattice resonances has been foremost studied by the group of Odom, who investigated the behavior of different lattice geometries prepared. Aside from this lithography‐based work, colloidal self‐assembly enables the preparation of plasmonic lattices on elastomers like PDMS.…”

“…However, within this arising field of mechanoplasmonics, the practical demonstrations of colloid‐based arrays featuring SLRs with tunable properties are still rare. A proof of concept was recently realized by the Odom group, using top‐down lithographic methods . In a process combining photolithography, etching, electron‐beam deposition, and lift‐off on a PDMS substrate, they showed reversible tuning of the optical response by mechanical deformation.…”

Topological Plasmonic Chain with Retardation and Radiative Effects

“…26 Plasmonic and photonic systems provide a powerful platform to examine topological insulators without the complication of interacting particles and with interesting additional properties like non-Hermiticity.…”

“…26 Plasmonic and photonic systems provide a powerful platform to examine topological insulators without the complication of interacting particles and with interesting additional properties like non-Hermiticity. 27−32 The lack of Fermi level simplifies the excitation of states, and the tunability made available by the larger scale allows for the study of disorder and defects in greater depth than electronic systems.…”

Light Absorption Enhancement by Employing A Plasmonic Nanobox Cavity Array

“…51,52 On the other hand, the electric field distribution at λ = 472 nm was confined at the top surface of the nanobox (tip mode) as well as the lower inside surface of the nanobox (cavity mode) configuration in Figure 2(d). 53 Interestingly, the near field pattern in the xz plane at λ = 568 nm as depicted in Figure 2(e), was greatly enhanced around the lower inside, middle outside, and top surfaces of the plasmonic nanobox, which is similar to the combination of the electric field patterns at 680 nm and 800 nm. In Figure 2(f), the electric field intensity profile at λ = 680 nm was greatly enhanced around the top surface of the nanobox (tip mode) while the electric field at the lower inner surface of the nanobox (cavity mode) was slightly amplified.…”