Femtosecond laser line-by-line tilted Bragg grating inscription in single-mode step-index TOPAS/ZEONEX polymer optical fiber.
Opt Lett
; 48(6): 1438-1441, 2023 Mar 15.
Article
in En
| MEDLINE
| ID: mdl-36946947
ABSTRACT
In this Letter, we demonstrate 8°-tilted fiber Bragg grating (TFBG) inscription in single-mode step-index TOPAS/ZEONEX polymer optical fibers (POFs) using a 520â
nm femtosecond laser and the line-by-line (LbL) writing technique. As a result of the tilt angle and the fiber refractive index, a large spectral range of cladding mode resonances covering 147â
nm is obtained. The evolution of the transmitted spectrum is analyzed as a function of the surrounding refractive index (SRI) in a large range from 1.30 to 1.50. The cutoff cladding mode shows a refractive index sensitivity of 507â
nm/RIU (refractive index unit). For single-resonance tracking near the cutoff mode, the sensitivity is at least 6â
nm/RIU, depending on the exact wavelength position of the cladding modes. The main originality of our work is that it produces, for the first time, to the best of our knowledge, a TFBG in POF that operates in the refractive index range of aqueous solutions. The sensing capability for a large range of refractive index values is also relevant for (bio)chemical sensing in different media.
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Database:
MEDLINE
Language:
En
Year:
2023
Type:
Article