UC Irvine

In this thesis, we investigate the pressure-dependent properties of low-order Fabry-Perot resonators composed of amorphous silicon nitride (a-SiN) coated with thin gold films on both sides under hydrostatic pressure. The gold layers play a dual role in the a-SiN Fabry- Perot resonator: they serve as mirrors to form the resonator while also supporting localized surface plasmon resonance (LSPR), which couples with the Fabry-Perot resonance to alter the spectral lineshape and peak position. Using a diamond anvil cell (DAC) system, we apply high hydrostatic pressure to the resonator, inducing a blueshift in the resonance and modifying the refractive index of the a-SiN. These changes arise from the interplay between the material’s structural, electronic, and optical properties under compression. This work highlights the tunability of a-SiN-based Fabry-Perot resonators through pressure, providing a promising alternative to temperature-based adjustments. Additionally, the thin-film a-SiN Fabry-Perot structure offers opportunities for advanced metasurface designs, expanding the potential of pressure-tunable photonic devices for applications in extreme environments and adaptive optical systems.