Programmable nanophotonic planar resonator filter-absorber based on phase-change InSbTe

Abstract

Reconfigurable plasmonic-photonic electromagnetic devices have been incessantly investigated for their great ability to optically modulate through external stimuli to meet today's emerging needs, with chalcogenide phase-change materials being promising candidates due to their remarkably unique electrical and optics, enabling new perspectives in recent photonic applications. In this work, we propose a reconfigurable resonator using planar layers of stacked ultrathin films based on Metal-dielectric-PCM, which we designed and analyzed numerically by the Finite Element Method (FEM). The structure is based on thin films of Gold (Au), aluminum oxide (Al2O3), and PCM (In3SbTe2) used as substrate. The modulation between the PCM phases (amorphous and crystalline) allows the alternation from the filter to the absorber structure in the infrared (IR) spectrum (1000–2500 nm), with an efficiency greater than 70% in both cases. The influence of the thickness of the material is also analyzed to verify tolerances for manufacturing errors and dynamically control the efficiency of transmittance and absorptance peaks. The physical mechanisms of field coupling and transmitted/absorbed power density are investigated. We also analyzed the effects on polarization angles for Transversal Electric (TE) and Transversal Magnetic (TM) polarized waves for both cases.

Hybrid Ghost Phonon Polaritons in Thin-Film Heterostructure

“…Here, we report hybrid g-PhPs supported in a heterostructure of calcite and an ultrathin film of phase change material (PCM) where the optical field is largely confined within and sharply decays outside the film. In our experiments, we used a thin film of plasmonic PCM In 3 SbTe 2 (IST) that undergoes a dielectric-to-metal phase transition upon crystallization, which provides an unprecedented large optical contrast over infrared and terahertz spectral range. − By introducing such a film, not only is the field confinement enhanced, but also an active manipulation of hybrid g-PhPs is realized via direct laser switching of crystalline microdomains or gratings in IST. With scanning near-field optical microscopy, we are able to measure the angle-dependent momentum distribution of hybrid g-PhPs and the standing waves in between IST gratings.…”