Paper
28 September 1999 Advances in fiber gratings: technology, applications, and reliability
Hans G. Limberger, Dimitris Varelas
Author Affiliations +
Abstract
Basic components and devices for optical fiber sensor and telecommunication networks should exhibit survival times of 20 to 40 years. Fiber gratings are important basic devices for such networks. This demands good thermal and mechanical reliability of the grating itself. However, as it will be shown in this paper, both reliability aspects depend strongly on factors like grating fabrication conditions, the fiber used, a possible photosensitization process, etc. The thermal stability of fiber gratings is strongly linked to the fiber, its co-dopants and possible photosensitization by hydrogen loading. Determining the electron distribution of the involved defects can assess the reliability. To a first approximation the decay is determined by the decay frequency v0. Good thermal stability over 25 years at 40 °C can be predicted for germanosilicate fibers if the gratings are annealed for 110 hours at T≈120 °C. Higher operating temperatures demand higher annealing temperatures for reasonable annealing times and do need therefore special protections like polyimide coatings. The mechanical breaking strength of fiber gratings is related to the grating fabrication process and fiber preparation. For telecommunication applications, gratings are in general fabricated off-line. In this case, careful chemical fiber stripping and handling is needed. When gratings are written using pulsed KrF excimer laser irradiation a considerable mechanical degradation is observed, which depends on the irradiation conditions. In contrary, frequency doubled CW-Ar+ laser irradiation almost preserves the median breaking stress. Gratings fabricated by one single laser shot or written through the fiber coating show almost no degradation. However, due to their low reflectivity the use of single shot gratings is mostly restricted to sensor applications. The fabrication of grating devices by irradiation through the coating is still limited to index modulations of 10-4 due to coating degradation.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hans G. Limberger and Dimitris Varelas "Advances in fiber gratings: technology, applications, and reliability", Proc. SPIE 10295, Reliability of Optical Fibers and Optical Fiber Systems: A Critical Review, 1029508 (28 September 1999); https://doi.org/10.1117/12.367127
Lens.org Logo
CITATIONS
Cited by 4 scholarly publications.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Reliability

Annealing

Networks

Excimer lasers

Fiber coatings

Fiber lasers

Fiber optics sensors

Back to Top