Abstract

We propose a cavity length demodulation method that combines virtual reference interferometry (VRI) and minimum mean square error (MMSE) algorithm for fiber-optic Fabry–Perot (F-P) sensors. In contrast to the conventional demodulating method that uses fast Fourier transform (FFT) for cavity length estimation, our method employs the VRI technique to obtain a raw cavity length, which is further refined by the MMSE algorithm. As an experimental demonstration, a fiber-optic F-P sensor based on a sapphire wafer is fabricated for temperature sensing. The VRI-MMSE method is employed to interrogate cavity lengths of the sensor under different temperatures ranging from 28°C to 1000°C. It eliminates the “mode jumping” problem in the FFT-MMSE method and obtains a precision of 4.8 nm, corresponding to a temperature resolution of 2.0°C over a range of 1000°C. The experimental results reveal that the proposed method provides a promising, high precision alternative for demodulating fiber-optic F-P sensors.

© 2018 Chinese Laser Press

Four-wavelength laser interferometry for the demodulation of dual-cavity fiber-optic extrinsic Fabry-Perot interferometric sensors

Yang Han, Yi Jiang, Jingshan Jia, and Yutong Zhang
Opt. Express 32(8) 14200-14210 (2024)

Wavelet phase extracting demodulation algorithm based on scale factor for optical fiber Fabry-Perot sensing

Baolin Zhang, Xinglin Tong, Pan Hu, Qian Guo, Zhiyuan Zheng, and Chaoran Zhou
Opt. Express 24(26) 29506-29511 (2016)

Least square fitting demodulation technique for the interrogation of an optical fiber Fabry–Perot sensor with arbitrary reflectivity

Wenyi Liu, Qianyu Ren, Pinggang Jia, Yingping Hong, Ting Liang, Jia Liu, and Jijun Xiong
Appl. Opt. 59(5) 1301-1306 (2020)

Improved spectral demodulation algorithm with EEMDAD for sapphire fiber Fabry–Perot high-temperature sensing

Shuang Wang, Meiyu Yan, Junfeng Jiang, Zhiyuan Li, Anqi Chen, Ke Tan, and Tiegen Liu
Appl. Opt. 61(28) 8405-8413 (2022)

Parallel demodulation system and signal-processing method for extrinsic Fabry–Perot interferometer and fiber Bragg grating sensors

Junfeng Jiang, Tiegen Liu, Yimo Zhang, Lina Liu, Ying Zha, Fan Zhang, Yunxin Wang, and Pin Long
Opt. Lett. 30(6) 604-606 (2005)