Simultaneous Measurement of Air Pressure and Temperature Using Fiber-Optic Cascaded Fabry-Perot Interferometer

• Published in: IEEE photonics journal Vol. 11; no. 1; pp. 1 - 10
• Main Authors: Li, Zhigang, Tian, Jiajun, Jiao, Yuzhu, Sun, Yunxu, Yao, Yong
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.02.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Air pressure and temperature measurement; Bandpass filters; Cavity resonators; Crystal fibers; Electron tubes; Fabrication; fabry-perot interferometer; Fabry-Perot interferometers; Fiber optics; Holes; Optical fibers; Photonic crystals; Pressure measurement; Sensitivity; Silicon compounds; Silicon dioxide; Temperature measurement; Temperature sensors
• ISSN: 1943-0655; 1943-0655; 1943-0647
• DOI: 10.1109/JPHOT.2018.2884776

We propose and demonstrate a fiber-optic cascaded-cavity Fabry-Perot interferometer (FPI) for simultaneous measurement of air pressure and temperature. The open-cavity hybrid FPI consists of an air-cavity and a silica-cavity formed by a section of silica tube and photonic crystal fiber, respectively. The air-cavity and silica-cavity exhibit different sensitivities to air pressure and temperature. Thus, the proposed sensor can be used to implement air pressure and temperature sensing simultaneously. The spectra of the air-cavity and silica-cavity are extracted from the total reflection spectrum with designed bandpass filters. The air pressure and temperature sensitivities of the air-cavity are 4.04 pm/kPa and 0.87 pm/°C, respectively, and those of the silica-cavity are 3.36 pm/kPa and 14.36 pm/°C, respectively. Moreover, the temperature and air pressure cross-sensitivity can be reduced by using a sensitivity coefficients matrix of two cavities. With the advantages of compact size, easy fabrication, and all-fiber structure, the proposed sensor is a potential candidate for practical applications.