Ultra-high-Q resonances in plasmonic metasurfaces

Abstract

Plasmonic nanostructures hold promise for the realization of ultra-thin sub-wavelength devices, reducing power operating thresholds and enabling nonlinear optical functionality in metasurfaces. However, this promise is substantially undercut by absorption introduced by resistive losses, causing the metasurface community to turn away from plasmonics in favour of alternative material platforms (e.g., dielectrics) that provide weaker field enhancement, but more tolerable losses. Here, we report a plasmonic metasurface with a quality-factor (Q-factor) of 2340 in the telecommunication C band by exploiting surface lattice resonances (SLRs), exceeding the record by an order of magnitude. Additionally, we show that SLRs retain many of the same benefits as localized plasmonic resonances, such as field enhancement and strong confinement of light along the metal surface. Our results demonstrate that SLRs provide an exciting and unexplored method to tailor incident light fields, and could pave the way to flexible wavelength-scale devices for any optical resonating application.

Enhanced generation of nondegenerate photon pairs in nonlinear metasurfaces

“…Accordingly, for the best SPDC enhancement, it would be most important to maintain consistent periodic nanopatterning over the whole spatial extent of the MS. Additionally, the MS dimensions should be sufficiently large, with tens or hundreds of periods in each spatial direction, to avoid limitations on the resonance Q factor. 6,34 These conditions can be achieved with the state-of-the-art nanofabrication facilities. For example, ultrahigh Q factors of over 10,000 in dielectric MSs were reported for extended BICs.…”

The Beginner's Guide to Chiral Plasmonics: Mostly Harmless Theory and the Design of Large‐Area Substrates

“…[ 90–94 ] In comparison to LSPR, SLR results in higher‐quality‐factor resonances, [ 90–94 ] which can go experimentally up to quality factors (Δλ/λ) above 2400. [ 95 ] Further, SLRs exhibit near‐field effects distributed over larger surface areas than highly confined LSPRs with longer lifetime due to lesser radiative losses. [ 96–99 ]…”

“…[ 212,213 ] Arranging the 3D intrinsic chiral crescents with broken mirror‐symmetry into a hexagonal lattice provided by nonclose packed colloidal particles [ 166 ] allows the coupling the dipolar plasmon resonances to lattice modes, and thus to form chiral surface lattice resonances (Figure 9c). [ 98,214 ] Although demonstrated in a proof‐of‐principle experiment of large‐areas, [ 98 ] their quality factors is not yet comparable to state‐of‐the‐art fabrication methods [ 95 ] or theoretical findings.…”

Plasmonic Narrowband Filter Based on an Equilateral Triangular Resonator with a Silver Bar

“…These ultrahigh Q-factors can be increased to above 1500 without an adhesive layer [28]. Saad Bin-Alam et al proposed a modified anapole resonator based on Hg with a high Q-factor and large thermal sensitivity of 17.14 MHz/degrees to realize high-precision temperature sensing [29]. Peter A et al illustrated a metasurface that consisted of hollow dielectric cuboids with an experimental Q-factor of 728 at 1505 nm by using silicon as the high index dielectric [30].…”