Reflectance characteristics of a two-cavity extrinsic Fabry-Perot optical fiber sensor were investigated using computer modeling. Calculations were performed using a plane wave-based approach, selected for clarity of results. Based on the modeling results, it can be concluded that the two-cavity Fabry-Perot interferometer can be used to measure two different quantities, such as refractive index and temperature, independently. It is also possible to use one of its cavities as a wavelength or optical path length reference, especially when a tunable laser is used as a light source. Spectral signal processing needed in such sensor is not substantially more complicated than that used in single cavity sensors.
Paweł Wierzba, Paweł Wierzba,
"Modeling of multi-cavity Fabry-Perot optical fiber sensors", Proc. SPIE 9816, Optical Fibers and Their Applications 2015, 98160V (17 December 2015); doi: 10.1117/12.2223011; https://doi.org/10.1117/12.2223011