A high-sensitivity fiber-optic gas pressure sensor based on a Fabry-Perot interferometer filled with epoxy resin adhesive is proposed. The factors of affecting the pressure sensitivity are theoretically analyzed and verified experimentally. In our experiment, the pressure sensitivity of the epoxy-filled sensor with the thinnest diaphragm thickness of 6.61 µm corresponding to the cavity length of 65.45 µm is −530.17 pm/kPa from 200 to 300 kPa. The sensitivity of the proposed pressure sensor with

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... the shortest cavity length of 90.43 µm corresponding to the film thickness of 10.65 µm is −378.18 pm/kPa from 200 to 300 kPa. To further improve the sensitivity, the proposed pressure sensor is optimized, which consists of two cascaded Fabry-Perot interferometers separated by a long section of single-mode fiber to form Vernier effect. Such a pressure sensor based on the epoxyfilled Fabry-Perot interferometer and the Vernier effect obtains a high sensitivity of 2.526 nm/kPa in the local measurement range of 233 to 259 kPa and a low detection limit of 0.00892 kPa. With the advantages of high sensitivity, compact structure and simple fabrication, the proposed pressure sensor has potential applications in the biomedical field and 2012. He is currently an Associate Professor and a Master's Supervisor of Hainan University. His main research area is optic communication sensing technology. Chaoyang Li received the Ph.D. degree from the University of California at Berkeley, Berkeley. He worked at the world-renowned Lawrence Berkeley Laboratory. He is currently a Professor and a Doctoral Supervisor of Hainan University. His main research interests are information and sensing chip technology.