Low-Dose Radiation-Induced Attenuation at InfraRed Wavelengths for P-Doped, Ge-Doped and Pure Silica-Core Optical Fibres

Exposing optical silica fibers to radiative environments leads to an increase of fiber attenuation. This gamma-sensitivity of the fibers is strongly wavelength dependent. Many papers already mentioned the strong radiation-induced attenuation (RIA) in the UV and visible ranges, which is explained by radiation-induced defects absorbing in these spectral ranges. However, the origin of RIA at longer wavelengths (lambda > 1000 nm) is less clear. An exception is phosphorous-doped fibers for which P1 defects absorbing around 1700 nm have already been highlighted. For fibers with no phosphorus, the RIA at near-infrared (NIR) wavelengths is usually assumed to be small as it results from the UV-visible absorption tail, which decreases with increasing wavelength. In this paper, we study three prototype silica based optical fibers and show that the RIA does not monotically decrease with increasing wavelength, highlighting RIA-contributions having their origins at NIR-wavelengths. We show that these NIR-absorbing defects are generally the main contributor to RIA at telecommunication wavelengths (1310 nm and 1550 nm), the impact of UV-visible absorption tail being secondary only. The nature of defects involved in these NIR absorptions depends on fiber composition. For fibers with no phosphorous, we propose self trapped hole defects (STH) as origin.

[1]  Yoshimichi Ohki,et al.  Improvement of Radiation Resistance of Pure Silica Core Fibers by Hydrogen Treatment , 1985 .

[2]  David L. Griscom,et al.  Defects in SiO[2] and related dielectrics : science and technology , 2000 .

[3]  H. Henschel,et al.  Radiation-induced optical fibre loss in the far IR , 1999, 1999 Fifth European Conference on Radiation and Its Effects on Components and Systems. RADECS 99 (Cat. No.99TH8471).

[4]  E. J. Friebele,et al.  Fundamental defect centers in glass: Electron spin resonance and optical absorption studies of irradiated phosphorus‐doped silica glass and optical fibers , 1983 .

[5]  Minoru Watanabe,et al.  Gamma-Ray Irradiation Effect on Loss Increase of Single Mode Optical Fibers, (I): Loss Increase Behavior and Kinetic Study , 1989 .

[6]  V. B. Neustruev,et al.  Colour centres in germanosilicate glass and optical fibres , 1994 .

[7]  Sylvain Girard,et al.  Analyse de la réponse des fibres optiques soumises à divers environnements radiatifs , 2003 .

[8]  G. C. Valley,et al.  Gamma and proton radiation effects in erbium-doped fiber amplifiers: active and passive measurements , 2001 .

[9]  Kazuya Saito,et al.  Fictive-temperature-dependence of photoinduced self-trapped holes in a-SiO 2 , 2003 .

[10]  L. Skuja.  Optically active oxygen-deficiency-related centers in amorphous silicon dioxide , 1998 .

[11]  E. Friebele,et al.  Radiation damage of optical fiber waveguides at long wavelengths. , 1982, Applied optics.

[12]  David L. Griscom,et al.  Radiation hardening of pure-silica-core optical fibers: Reduction of induced absorption bands associated with self-trapped holes , 1997 .

[13]  F. Berghmans,et al.  Study of the radiation-induced optical sensitivity in erbium and aluminium doped fibres , 2003, Proceedings of the 7th European Conference on Radiation and Its Effects on Components and Systems, 2003. RADECS 2003..

[14]  Kawamura,et al.  Photochemical reactions in GeO2-SiO2 glasses induced by ultraviolet irradiation: Comparison between Hg lamp and excimer laser. , 1995, Physical review. B, Condensed matter.

[15]  David L. Griscom,et al.  THE NATURES OF POINT DEFECTS IN AMORPHOUS SILICON DIOXIDE , 2000 .

[16]  Martin A. Putnam,et al.  Radiation effects in erbium-doped optical fibres , 1992 .

[17]  J. Nishii,et al.  Pair generation of Ge electron centers and self-trapped hole centers in GeO 2 − S i O 2 glasses by KrF excimer-laser irradiation , 1999 .

[18]  L. S. Kornienko,et al.  Spectroscopic Manifestations of Self-Trapped Holes in Silica Theory and Experiment , 1989 .

[19]  X. Bao,et al.  Gamma-induced attenuation in normal single-mode and multimode, Ge-doped and P-doped optical fibers: A fiber optic dosimeter for low dose levels , 2000 .

[20]  Y. Sasajima,et al.  Optical transitions of self-trapped holes in amorphousSiO2 , 2003 .