title: Radiation tolerant fiber Bragg gratings for high temperature monitoring at MGy dose levels.
abstract: We report a method for fabricating fiber Bragg gratings (FBG) resistant to very severe environments mixing high radiation doses (up to 3 MGy) and high temperatures (up to 230°C). Such FBGs have been written in two types of radiation resistant optical fibers (pure-silica and fluorine-doped cores) by exposures to a 800 nm femtosecond IR laser at power exceeding 500 mW and then subjected to a thermal annealing treatment of 15 min at 750°C. Under radiation, our study reveals that the radiation induced Bragg wavelength shift (BWS) at a 3 MGy dose is strongly reduced compared to responses of FBGs written with nonoptimized conditions. The BWS remains lower than 10 pm for temperatures of irradiation ranging from 25°C to 230°C without noticeable decrease of the FBG peak amplitude. For an applicative point of view, this radiation induced BWS corresponds to an additional error on the temperature measurements lower than 1.5°C, opening the way to the development of radiation-tolerant multi-point temperature sensors for nuclear industry.
authors.forename: A
authors.initials: A
authors.lastname: Morana
authors.forename: S
authors.initials: S
authors.lastname: Girard
authors.forename: E
authors.initials: E
authors.lastname: Marin
authors.forename: C
authors.initials: C
authors.lastname: Marcandella
authors.forename: P
authors.initials: P
authors.lastname: Paillet
authors.forename: J
authors.initials: J
authors.lastname: Périsse
authors.forename: J-R
authors.initials: JR
authors.lastname: Macé
authors.forename: A
authors.initials: A
authors.lastname: Boukenter
authors.forename: M
authors.initials: M
authors.lastname: Cannas
authors.forename: Y
authors.initials: Y
authors.lastname: Ouerdane