Green Open AccessLaser-induced graphene from commercial polyimide coated optical fibers for sensor development
Date Issued
May 1, 2023
Abstract
Direct laser scribing (DLS) technology is applied to commercial polyimide (PI) coated optical fibers producing laser-induced graphene (LIG) coated optical fibers. The PI-coated optical fiber is first inscribed with off-center Bragg gratings via point-by-point method using a femtosecond laser system. Then, the off-center Bragg grating is irradiated with a CO2 laser and the PI coating is photothermally converted into LIG without affecting the grating. Scanning electron microscopy (SEM) and Raman spectroscopy prove the presence of the laser-induced graphene layer on the optical fiber, and Fourier transform infrared (FTIR) spectroscopy confirms that all the PI coating was converted into LIG. The resulting LIG-coated off-center Bragg grating (FBG) sensors respond to variations of the surrounding refractive index (RI) with a sensitivity of 38.08 ± 1.57 nm per RI units (RIU). In addition, after removal of the PI coating, obtaining a bare-FBG, the sensitivity decreases to 25.63 ± 0.66 nm RIU−1. Therefore, this strategy, here reported for the first time, paves the way to produce promising novel optical transducers aiming to develop bio- and chem-sensing devices.
Affiliation
Scopus Subject Areas
Electronic, Optical and Magnetic Materials
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Atomic and Molecular Physics, and Optics
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Electrical and Electronic Engineering