Temperature Stability and Spectral Tuning of Long Period Fiber Gratings Fabricated by Femtosecond Laser Direct Writing

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Viveiros, D (Author) FCUP; de Almeida, JMMM (Author) FCUP; Coelho, L (Author) FCUP; Vasconcelos, H (Author) Other; Maia, JM (Author) Other; Amorim, VA (Author) Other; Jorge, PAS (Author) FCUP; Marques, PVS (Author) FCUP

Journal

Title: Sensors

Vol. 20

Pages: 1-15

ISSN: 1424-3210

Publisher: MDPI

Indexing

ISI Web of Knowledge - 7 Citations

Scopus - 9 Citations

Other information

Authenticus ID: P-00S-E8Z

DOI: 10.3390/s20143898

Abstract (EN): Long period fiber gratings (LPFGs) were fabricated in a standard single mode fiber (SMF-28e) through femtosecond (fs) laser direct writing. LPFGs with longer and shorter periods were fabricated, which allows coupling from the fundamental core mode to lower and higher order asymmetric cladding modes (LP(1,6)and LP1,12, respectively). For the grating periods of 182.7 and 192.5 mu m, it was verified that the LP(1,12)mode exhibits a TAP at approximately 1380 and 1448 nm in air and water, respectively. Characterization of the LPFGs subjected to high-temperature thermal treatment was accomplished. Fine-tuning of the resonance band's position and thermal stability up to 600 degrees C was shown. The temperature sensitivity was characterized for the gratings with different periods and for different temperature ranges. A maximum sensitivity of -180.73, and 179.29 pm/degrees C was obtained for the two resonances of the 182.7 mu m TAP LPFG, in the range between 250 and 600 degrees C.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15