Photonic Sensors, 2017, 7 (4): 336, 网络出版: 2018-01-09
HCPCF-Based In-Line Fiber Fabry-Perot Refractometer and High Sensitivity Signal Processing Method
HCPCF-Based In-Line Fiber Fabry-Perot Refractometer and High Sensitivity Signal Processing Method
Optical fiber sensor in-line Fabry-Perot interferometer hollow-core photonic crystal fiber refractive index spectrum differential integration method
摘要
Abstract
An in-line fiber Fabry-Perot interferometer (FPI) based on the hollow-core photonic crystal fiber (HCPCF) for refractive index (RI) measurement is proposed in this paper. The FPI is formed by splicing both ends of a short section of the HCPCF to single mode fibers (SMFs) and cleaving the SMF pigtail to a proper length. The RI response of the sensor is analyzed theoretically and demonstrated experimentally. The results show that the FPI sensor has linear response to external RI and good repeatability. The sensitivity calculated from the maximum fringe contrast is –136 dB/RIU. A new spectrum differential integration (SDI) method for signal processing is also presented in this study. In this method, the RI is obtained from the integrated intensity of the absolute difference between the interference spectrum and its smoothed spectrum. The results show that the sensitivity obtained from the integrated intensity is about –1.34×105 dB/RIU. Compared with the maximum fringe contrast method, the new SDI method can provide the higher sensitivity, better linearity, improved reliability, and accuracy, and it’s also convenient for automatic and fast signal processing in real-time monitoring of RI.
Xiaohui LIU, Mingshun JIANG, Qingmei SUI, Xiangyi GENG, Furong SONG. HCPCF-Based In-Line Fiber Fabry-Perot Refractometer and High Sensitivity Signal Processing Method[J]. Photonic Sensors, 2017, 7(4): 336. Xiaohui LIU, Mingshun JIANG, Qingmei SUI, Xiangyi GENG, Furong SONG. HCPCF-Based In-Line Fiber Fabry-Perot Refractometer and High Sensitivity Signal Processing Method[J]. Photonic Sensors, 2017, 7(4): 336.