Research papers - IEEE Xplore: 17 December 2021
Accuracy Evaluation of a CDM-WDM Interrogator for Quasi-Distributed FBG Sensing
Marek Götten, Steffen Lochmann, Andreas Ahrens, Eric Lindner, Johan Vlekken, Jan Van Roosbroeck.
Short description
This work evaluates the accuracy of a code-division multiplex (CDM) - wavelength-division multiplex (WDM) inter-rogation system for massive serial fiber optical sensing using fiber-Bragg gratings. The standard deviation of wavelength detection dependent on a signal-to-noise-ratio, referred to as static deviations, is measured to be less than 3 pm. Two consecutive correlation steps are subtracted. Dynamic influences occur due to a wavelength shift between the correlation steps. They are investigated using a gradient from a linear regression. Dynamic self interference ranges from 0 pm/pm (picometer deviation per picometer wavelength shift) for the maximum peak to -3.47 pm/pm at 20 % of the maximum peak height. Dynamic multi-user interference, caused by spectral overlapping sensors, starts at -0.5 pm/pm down to -7.27 pm/pm, which makes this system well competitive to other multiplexing techniques.