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This paper reports on the radiation induced attenuation of light at 1310 nm and 1550 nm in 12 commercially available single mode (SM) optical fibers. The fiber samples are exposed to gamma rays from a [sup.60]Co source and to a high energy physics radiation field. The attenuation is studied as a function of total dose, dose rate, light power and temperature. Radiation hard fibers from one manufacturer show an extraordinary low attenuation for light at 1310 nm that does not exceed 5 dB/km even after a total dose of 1 MGy. 2500 km of this type of fiber have been produced by the manufacturer and quality assurance measurements of the production batches are presently ongoing. Index Terms--Gamma rays, high energy radiation field, industrial production, optical fibers, quality assurance, radiation induced attenuation.

The radiation-induced Bragg wavelength shift (BWS) was measured with type I gratings made of 12 fibers with very different composition, i.e., of fibers with an extremely different radiation-induced attenuation. With two of the fibers fabrication parameters like laser intensity, hydrogen loading, and annealing conditions after grating inscription were varied. With another fiber type I and type II gratings were made by a completely different process. With gratings made under identical conditions of the 12 fibers the radiation-induced BWS only varied by about a factor of three. Varying the fabrication parameters led to BWS differences up to nearly a factor of ten. Index Terms--Fiber Bragg gratings, gamma radiation, optical fiber sensor, radiation effects.

This paper reports on the radiation induced attenuation of light at 1310 nm and 1550 nm in 12 commercially available single mode (SM) optical fibers. The fiber samples are exposed to gamma rays from a 60Co source and to a high energy physics radiation field. The attenuation is studied as a function of total dose, dose rate, light power and temperature. Radiation hard fibers from one manufacturer show an extraordinary low attenuation for light at 1310 nm that does not exceed 5 dB/km even after a total dose of 1 MGy. 2500 km of this type of fiber have been produced by the manufacturer and quality assurance measurements of the production batches are presently ongoing. [ABSTRACT FROM AUTHOR]

This Letter reports the first, to the best of our knowledge, spectral radiation induced attenuation (RIA) measurements of nested anti-resonant nodeless hollow-core fibers (NANFs). A 5-tube NANF, alongside a solid-core single-mode radiation resistant fiber (SM-RRF), was irradiated under γ-ray up to 101 kGy (SiO 2 ) and under x-ray up to 241 kGy (SiO 2 ). No RIA was observed in the NANF in the second half of the O-band, the S-band, the C-band, and the L-band. The NANF showed a reduction of absorption bands associated with water and HCl under irradiation. Three new attenuation peaks were radiolytically induced and are attributed to the creation of HNO 3 . These peaks are centered respectively at 1441 nm, 1532 nm, and 1628 nm, with a full width at half maximum (FWHM) of, respectively, 10 nm, 12 nm, and 12 nm. These results demonstrate that the wide bandwidth range of NANFs is essentially unaffected by radiation, but the internal gas contents of the NANF must be managed to avoid producing undesirable spectral features through radiolytic reactions. Wide spectral regions almost unaffected by the ionizing radiation could open new possibilities for the use of NANF in harsh radiation environments.