Multifunctional Barophotonic Control of Resonators and Metasurfaces

TL;DR

This paper demonstrates pressure-tunable nanophotonic devices using silicon nitride, enabling reconfigurable optical functionalities such as resonance tuning and polarization conversion under extreme pressures up to 5 GPa.

Contribution

It introduces the first extreme-pressure-tunable, polarization-converting metasurface, expanding the capabilities of pressure-controlled nanophotonics.

Findings

Resonance shift of up to 30 nm under 5 GPa pressure

Refractive index decrease of up to 4% at high pressure

Design of a polarization-converting metasurface tunable by pressure

Abstract

Actively tunable nanophotonic platforms that control light-matter interactions enable reconfigurable optical systems and programmable photonic integrated circuits. Hydrostatic pressure provides a noninvasive and material-agnostic mechanism for modulating the refractive index and resonance conditions without introducing free carriers or structural damage. Here, we demonstrate multiple pressure-dependent functionalities in silicon nitride nanostructures, including resonance tuning, refractive index modulation, and polarization state conversion. Applying a pressure of up to 5 GPa, we observe a Fabry-P\'erot resonance shift of up to 30 nm and a relative refractive index decrease of up to 4%. Based on the results, we design and examine, to the best of our knowledge, the first extreme-pressure-tunable, polarization-converting metasurface, which tunes the ellipticity and orientation angle of the output light. These findings establish pressure-controllable silicon nitride as a viable platform for reconfigurable photonics and extreme-environment nanophotonic systems, including deep-ocean exploration, planetary interiors, and space applications.