Ultra-Compact and Highly Sensitive Pressure Sensor Based on a 2D Photonic Crystal Square-Ring Resonator for High-Pressure Range (0 to 10 GPa)

This study presents an optical platform for pressure sensing based on a square-ring resonator. Numerical simulations reveal a shift in the resonant frequency towards lower frequencies, concomitantly with a shift in the resonant wavelength towards higher wavelengths, in response to an increase in applied pressure. Two simulation methodologies, the plane wave expansion (PWE) method and the finite-difference time-domain (FDTD) method, were employed to extract the guided mode and analyze the functional characteristics of the proposed sensor under varying pressure constraints. The envisioned structure is distinguished by a high-quality factor, a sensitivity of approximately 4.39 nm/GPa over a dynamic range from 0 to 10 GPa, and an ultra-compact footprint of 274 μm². These properties render this structure particularly suitable for integration into microscale photonic integrated circuits.