Open AccessSignal processing method based on group delay calculation for distributed Bragg wavelength shift in optical frequency domain reflectometry
Author(s) -
Daichi Wada,
Hirotaka Igawa,
Hideaki Murayama,
Tokio Kasai
Publication year - 2014
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.22.006829
Subject(s) - reflectometry , optics , fiber bragg grating , wavelength , signal (programming language) , signal processing , time domain , fast fourier transform , fourier transform , materials science , group delay and phase delay , signal to noise ratio (imaging) , physics , bandwidth (computing) , computer science , digital signal processing , telecommunications , algorithm , quantum mechanics , computer hardware , computer vision , programming language
A signal processing method based on group delay calculations is introduced for distributed measurements of long-length fiber Bragg gratings (FBGs) based on optical frequency domain reflectometry (OFDR). Bragg wavelength shifts in interfered signals of OFDR are regarded as group delay. By calculating group delay, the distribution of Bragg wavelength shifts is obtained with high computational efficiency. We introduce weighted averaging process for noise reduction. This method required only 3.5% of signal processing time which was necessary for conventional equivalent signal processing based on short-time Fourier transform. The method also showed high sensitivity to experimental signals where non-uniform strain distributions existed in a long-length FBG.