An interferometric structure with a dual-resonance long period grating for strain sensing

Spectral characteristics and amplitude tunability of a long period grating with a dual- resonance inside fiber loop mirror are studied in terms of applied stress caused by elongation. Inserting the polariza-tion controller between grating and part of polarization maintaining fiber in the loop structure enables tuning of resonance and interferometric peaks. The maximum sensitivity of demonstrated sensor is of 1.943 dB/mε for the range of 1.1–4.4 mε. Combination of these two optical components allows to measure strain in a wider range comparing with sensors based on standard long period grating.

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1. This research was funded by the financial support of the Natural Sciences and Engineering Research Council of Canada for the SPI/NSERC Industrial Research Chair in Photonic Sensing Systems for Safety and Security Monitoring. The investigation was also supported by the internal MUT project no. RMN 08/690, as well as the Ministry of National Defence Republic of Poland project no. GBMON/13-995/2018/WAT.

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2. Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).