1. Laser-induced graphene from commercial polyimide coated optical fibers for sensor development.
- Author
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Martins, Luís, Kulyk, Bohdan, Theodosiou, Antreas, Ioannou, Andreas, Moreirinha, Catarina, Kalli, Kyriacos, Santos, Nuno, Costa, Florinda, Pereira, Sónia O., and Marques, Carlos
- Subjects
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OPTICAL coatings , *BRAGG gratings , *OPTICAL fiber detectors , *GRAPHENE , *OPTICAL fibers , *OPTICAL transducers , *FEMTOSECOND lasers - 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 CO 2 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 R I U − 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. • Direct laser scribing technology applied to commercial polyimide optical fibers. • Laser-induced graphene produced directly on optical fiber for sensing. • The resulting LIG-coated off-center FBG sensors respond to variations of the surrounding RI. • High sensitivity compared with after removal of the PI coating. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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