title: Real-time analysis of arc-induced Long Period Gratings under gamma irradiation.
abstract: In this paper, we present a comparative experimental and theoretical study on gamma radiation sensitivity of Long Period Gratings (LPGs), fabricated by electric arc discharge technique, as monitored in three single mode optical fibers supplied by different manufacturers. A real-time measurement of LPGs' wavelength shift was performed until a total dose of 35 kGy was reached, with average dose rate of 0.18 kGy/h, the irradiation being done at room temperature. In one case, a maximum radiation sensitivity of 1.34 nm/kGy was recorded for doses up to 0.5 kGy. Moreover, by combining experimental results with numerical simulations, it was found that changes occurred in the core refractive index of the irradiated optical fibers up to 2.5 ∙ 10-5. The increase of the core thermo-optic coefficient up to 1.5 ∙ 10-8/°C was observed as well.
authors.affiliation: Department of Engineering, University of Naples "Parthenope", Centro Direzionale Isola C4, Naples 80143, Italy.
authors.forename: Flavio
authors.initials: F
authors.lastname: Esposito
authors.affiliation: Department of Engineering, University of Naples "Parthenope", Centro Direzionale Isola C4, Naples 80143, Italy.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Ranjan
authors.affiliation: National Institute Laser, Plasma and Radiation Physics, Center for Advanced Laser Technologies, 409 Atomiştilor St., Măgurele RO-077125, Romania.
authors.forename: Andrei
authors.initials: A
authors.lastname: Stăncălie
authors.affiliation: National Institute Laser, Plasma and Radiation Physics, Center for Advanced Laser Technologies, 409 Atomiştilor St., Măgurele RO-077125, Romania.
authors.forename: Dan
authors.initials: D
authors.lastname: Sporea
authors.affiliation: "Horia Hulubei" National Institute of Physics and Nuclear Engineering, IRASM Radiation Processing Department, 30 Reactorului St., Măgurele RO-077125, Romania.
authors.forename: Daniel
authors.initials: D
authors.lastname: Neguţ
authors.affiliation: Apel Laser, 15 Vintila Mihăilescu St., Bucharest RO-060394, Romania.
authors.forename: Nicu
authors.initials: N
authors.lastname: Becherescu
authors.affiliation: Department of Engineering, University of Naples "Parthenope", Centro Direzionale Isola C4, Naples 80143, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Campopiano
authors.affiliation: Department of Engineering, University of Naples "Parthenope", Centro Direzionale Isola C4, Naples 80143, Italy.
authors.forename: Agostino
authors.initials: A
authors.lastname: Iadicicco