Low-Cost Wideband Interrogation System for Fiber Optic Sensors

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Araujo, JCC (Author) Other; dos Santos, PSS (Author) Other; Dias, B (Author) Other; de Almeida, JMMM (Author) FCUP; Coelho, LCC (Author) FCUP

Journal

Title: IEEE Sensors Journal

Vol. 23

ISSN: 1530-437X

Publisher: IEEE

Indexing

ISI Web of Knowledge - 0 Citations

Other information

Authenticus ID: P-00Y-CBY

DOI: 10.1109/jsen.2023.3272368

Abstract (EN): The interrogation of optical fiber sensors (OFS) often relies on complex devices such as optical spectrum analyzers (OSAs) that are expensive with low portability and mainly suited to laboratory measurements or dedicated interrogation systems with limited spectral range. An interrogation unit was designed and fabricated using a photodetector combined with a micro-electromechanical system and a Fabry-Perot interferometer (MEMS-FPI) working as a tunable filter with a response in the range 1350-1650 nm. Deconvolution techniques were applied to mitigate the effect of the broadband response of the tunable filter on the measured signal. The performance of the unit was validated with the interrogation of long-period fiber gratings (LPFGs) as temperature, refractive index (RI), and relative humidity (RH) sensors. For the temperature, a sensitivity of 0.135 +/- 0.007 nm/degrees C was obtained, which showed a 4.9% relative error when compared to the same measurement with an OSA. For the RI, a sensitivity of 147 +/- 11 nm/RIU was obtained, which showed a relative error lower than 1% when compared to the OSA. For the humidity, sensitivities of 0.742 +/- 0.005 and 0.056 +/- 0.006 nm/%RH were obtained, with errors of 2.75% and 6.67%, respectively, when compared to a commercial dedicated interrogation system. The low relative error obtained when compared to commercial alternatives shows the potential of the system to be used in real-time applications that require portability, low cost, energy efficiency, and capacity for integration in dedicated systems.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8