Switchable Gratings for Ultracompact and Ultrahigh Modulation Depth Plasmonic Switches

Abstract

Plasmonic interconnects present a compact platform for high modulation-depth optical switches. Conventional plasmonic switching approaches depend on modifying the dispersion of the surface plasmon polariton (SPP) wave at the metal/dielectric interface. Here, we introduce a novel scheme for ultracompact and high modulation depth (MD) plasmonic switching using a phase-change material-based switchable grating consisting of antimony trisulfide (Sb2S3). In its ON state, the switchable grating excites surface plasmon polaritons (SPP) and bulk plasmon polaritons (BPPs) in plasmonic films and hyperbolic metamaterials (HMMs), respectively. The SPP switch has a footprint of 23.1 µm2 and a MD of up to 40 dB. The BPP switch has a footprint of 13.12 μm2 and a MD of 29.7 dB. The BPP switch enjoys a broadband MD from 299 to 375 THz. Concurrently, we show that the same switchable grating on plasmonic film and on HMM is a reflection-based optical switch. Finally, we present a novel scheme for non-local control over the spontaneous emission rate and out-coupled power from emitters embedded in HMMs.