Reconfigurable Plasmonics Enabled by Low-Loss Phase Change Materials

The dynamic modulation of the optical response of plasmonic systems and devices by optical, mechanical and electrical stimuli is crucial for advancing nanophotonic applications such as optical switches, modulators, reconfigurable antennas, LIDAR system, surface-enhanced spectroscopies and photonic integrated circuits. In this contribution, we present an innovative approach to achieving tunable plasmonic properties by integrating phase-change materials (PCMs) with plasmonic systems. Specifically, we explore the dynamic plasmonic response of of low-loss PCMs of group III (Ga, In) and group-V (Sb) chalcogenides such as GaS, In2S3, Sb2Se3 and S2S3 also coupled with gold (Au) and gallium (Ga) plasmonic gratings and nanoparticle (NPs). We present active systems spanning from prtiodic gratings, to hybrid core-shell phase-change plasmonic NPs, to disk-shaped metasurfaces with PCM sandwiched between plasmonic elements and dielectrics. We show their active responsible tunable in a broad range from UV-VIS to IR. In these active heterostructures, the optical response of the plasmonic, traditionally fixed by design parameters during fabrication, can now be spectrally tuned through the reversible phase transitions of the incorporated PCM layer. We successfully demonstrate the reversible and tunable plasmonic response of the fabricated active heterostructures through controlled low-energy (in the nJ-fJ range) thermal, laser and electrically (low-voltage induced reversible amorphous-to-crystalline (and viceversa) phase change of the PCM. Engineered applications of those dynamics plasmonic structures in optical switches, light modulators, broadband plasmonically enhanced photodetectors and switchable scattering directionality nanoantennas will be demonstrated.<br/><br/>ACKNOWLEDGEMENTS: The authors acknowledge the support from the European Union's Horizon 2020 research and innovation program (No 899598 - PHEMTRONICS) the use of the ELI Beamlines Facility, Extreme Light Infrastructure ERIC. C.L. and S.C. acknowledge the support from the French National Research Agency (ANR) under the project MetaOnDemand (ANR-20-CE24-0013). S.V-M. and S.E. acknowledge the support by the project Advanced research using high intensity laser produced photons and particles (ADONIS) CZ.02.1.01/0.0/0.0/16_019/0000789 from European Regional Development Fund (ERDF). Y.G. acknowledge founding from a Ramon y Cajal Fellowship (RYC2022-037828-I).