We report on an incoherent OFDR interrogator of FBG arrays based on the concept of dispersive wavelength to time delay mapping. The system is specifically designed to show stability to environmental thermal variations by the incorporation of a composite dispersive delay and weak broadband reflectors for delay and dispersion monitoring. Dispersion is imparted by the combination of a fiber coil and an athermally-packaged chirped fiber Bragg grating for dispersion compensation. Using differential measurements over a single acquisition trace, the values of Bragg wavelengths and dispersion are determined from the delays experienced by the FBGs and by additional reference wavelengths reflected in the broadband reflectors. The results show maximum deviations of 20 pm and 0.2 ps/nm with respect to OSA measurements of Bragg wavelengths and nominal dispersion values, respectively.

Date Published: 30 May 2016
PDF: 4 pages
Proc. SPIE 9916, Sixth European Workshop on Optical Fibre Sensors, 99161K (30 May 2016); doi: 10.1117/12.2236654

Published in SPIE Proceedings Vol. 9916:
Sixth European Workshop on Optical Fibre Sensors
Elfed Lewis, Editor(s)