Open AccessIterative normalized cross-correlation method for absolute optical path difference demodulation of dual interferometers
Author(s) -
Guomeng Zuo,
Haoliang Hu,
Shiyu Li,
Yang Zhao,
Jing Chen,
Yuhao Huang,
Yingying Qu,
Li Xia
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.423326
Subject(s) - demodulation , interference (communication) , optics , cross correlation , optical path , astronomical interferometer , optical path length , interval (graph theory) , interferometry , physics , algorithm , computer science , mathematics , telecommunications , statistics , channel (broadcasting) , combinatorics
It is still a challenge to realize the absolute optical path difference (OPD) demodulation of multi-interference systems with a narrow spectral interval and small OPD interval. In this paper, an iterative normalized cross-correlation algorithm is firstly proposed for demodulating the multiple absolute OPDs of a dual-interference system and applied to optical fiber sensing system. By constructing a template function in combined form, the optimal solutions of its components and OPDs are solved iteratively based on the reconstruction matrix method and cross-correlation algorithm, respectively. The simulation and experiment show that the demodulation accuracies near the OPDs of 560 µm and 660 µm are both up to 5 nm in different spectral intervals from 45 to 80 nm. The simulation results show that all demodulation precisions at the spectral interval of 55 nm do not exceed 4 nm when the OPD changes in the range of 650-670 µm. Besides, the experimental verification shows the temperature accuracy (0.125 °C) with 95% confidence of T-distribution is very close to the control accuracy (0.1 °C). The proposed algorithm can improve the multiplexing capability of optical fiber sensor system and reduce its cost.