Design and Modeling of Highly Sensitive Lossy Mode Resonance-Based Fiber-Optic Pressure Sensor

This paper for the first time presents design and theoretical model for a fiber-optic pressure sensor based on a highly sensitive phenomenon of lossy mode resonance (LMR). Unlike transmission-based sensors, the proposed LMR-based pressure sensor works in reflection mode where sensing signal is measured in terms of the retro-reflection spectra. A detailed analysis of zinc oxide (ZnO) coated reflection-based LMR pressure sensor has been carried out. Also to improve sensitivity of the proposed sensor, an additional film of halfnium dioxide (HfO
₂
) is considered, and the combined effect of ZnO and oxide thickness ratio on the sensitivity has been investigated. Maximum sensitivity of the proposed pressure sensor is
$2~\mu \text {m}/\text {MPa}$
, which is higher than the previously reported popular fiber Bragg grating, interference and surface plasmon resonance-based pressure sensors. Additional feature of the proposed sensor is that one can achieve a tunable sensitivity and operating range only by changing the thickness ratio of ZnO and oxide overlay.