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 (HfO2) 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 m/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.