title: A polarized low-coherence interferometry demodulation algorithm by recovering the absolute phase of a selected monochromatic frequency.
abstract: A demodulation algorithm based on absolute phase recovery of a selected monochromatic frequency is proposed for optical fiber Fabry-Perot pressure sensing system. The algorithm uses Fourier transform to get the relative phase and intercept of the unwrapped phase-frequency linear fit curve to identify its interference-order, which are then used to recover the absolute phase. A simplified mathematical model of the polarized low-coherence interference fringes was established to illustrate the principle of the proposed algorithm. Phase unwrapping and the selection of monochromatic frequency were discussed in detail. Pressure measurement experiment was carried out to verify the effectiveness of the proposed algorithm. Results showed that the demodulation precision by our algorithm could reach up to 0.15kPa, which has been improved by 13 times comparing with phase slope based algorithm.
authors.affiliation: College of Precision Instrument & Optoelectronics Engineering, Tianjin University, Key Laboratory of Optoelectronics Information Technology, Tianjin 300072,China. jiangjfjxu@tju.edu.cn
authors.forename: Junfeng
authors.initials: J
authors.lastname: Jiang
authors.forename: Shaohua
authors.initials: S
authors.lastname: Wang
authors.forename: Tiegen
authors.initials: T
authors.lastname: Liu
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
authors.forename: Jinde
authors.initials: J
authors.lastname: Yin
authors.forename: Xiange
authors.initials: X
authors.lastname: Meng
authors.forename: Yimo
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.forename: Zunqi
authors.initials: Z
authors.lastname: Qin
authors.forename: Fan
authors.initials: F
authors.lastname: Wu
authors.forename: Dingjie
authors.initials: D
authors.lastname: Li