Extremely Narrow and Actively Tunable Mie Surface Lattice Resonances in GeSbTe Metasurfaces: Study

Abstract

Mie surface lattice resonances (SLRs) supported by periodic all-dielectric nanoparticles emerge from the radiative coupling of localized Mie resonances in individual nanoparticles through Rayleigh anomaly diffraction. To date, it remains challenging to achieve narrow bandwidth and active tuning simultaneously. In this work, we report extremely narrow and actively tunable electric dipole SLRs (ED-SLRs) in Ge2Se2Te5 (GST) metasurfaces. Simulation results show that, under oblique incidence with TE polarization, ED-SLRs with extremely narrow linewidth down to 12 nm and high quality factor up to 409 can be excited in the mid-infrared regime. By varying the incidence angle, the ED-SLR can be tuned over an extremely large spectral region covering almost the entire mid-infrared regime. We further numerically show that, by changing the GST crystalline fraction, the ED-SLR can be actively tuned, leading to nonvolatile, reconfigurable, and narrowband filtering, all-optical multilevel modulation, or all-optical switching with high performance. We expect that this work will advance the engineering of Mie SLRs and will find intriguing applications in optical telecommunication, networks, and microsystems.

Interdisk spacing effect on resonant properties of Ge disk lattices on Si substrates

“…Particular attention is paid to the study of the interaction of resonant modes, excited in individual dielectric particles, with lattice modes. In this case, it is reasonable to expect that the role of lattice modes will increase with a decrease in the interparticle spacing as a result of an increase in the overlap of their fields and the appearance of diffraction effects 27 – 29 .…”

Polarization-independent resonant lattice Kerker effect in phase-change metasurface

“…At λ = 4.61 µm, the electric field distributions show a circulation inside the GST disk, corresponding to a magnetic dipole, and the strongly enhanced electric field extends over large volumes, as shown by figure 3(c). These are typical characteristics of the MD-SLR [32,[43][44][45]. At λ = 4.67 µm, figure 3(d) shows that the electric field is aligned with the incident field and is greatly enhanced and extended over large volumes, confirming the excitation of the ED-SLR [32,[43][44][45].…”

Resonant Critical Coupling of Surface Lattice Resonances with a Fluorescent Absorptive Thin Film

“…Therefore, we obtain the following equations that describe our nanoparticle array embedded in an absorptive thin film (4) and (5) The TE-/TM-polarized transmissivity and reflectivity derived from eqs 4 and 5 are ( 6) and (7) under the steady-state condition, which are Fano-like spectra. 36 We then derive the absorptivity of the nanoparticle array by considering , where we find the absorptivity to be (see the Supporting Information) (8) under the steady-state solution, and…”

“…Surface lattice resonance (SLR) is a photonic resonance supported on nanoparticles arranged in a one-, two-, or three-dimensional periodic structure. − SLR has gained extensive attention through its potential in significantly improving light–matter interaction by introducing a confinement in the electromagnetic (EM) field beyond the diffraction limit and enhancing the field strength. − The nanoparticle arrays also possess great versatility in design and tunability, including the geometry of the array as well as the choice of materials used in the nanoparticle and the environment, and have found a wide range of applications in various fields, such as biosensing, , photovoltaic, , quantum optics, , nanolasing, , surface-enhanced spectroscopy, etc.…”