Irradiation Effects in Optical Fibers

摘要: Intrinsic and extrinsic optical fiber-based sensors are promising devices to be used in very different complex environments, by their nature: capabilities work under electromagnetic fields; possibility carry multiplexed signals (time, wavelength multiplexing); small size low mass; ability handle multi-parameter measurements distributed configuration; monitor sites far away from the controller. In case of fibers, incorporated into various types actuators, free additional hazards (i.e. fire, explosion), made them candidates operate adverse conditions as those required space applications terrestrial nuclear facilities (Alam et. al.a, 2006; Alam et al.b, Berghmans al., 2008; Ott, 2002). environments fibers found an application niche communication links, embedded all-fiber or hybrid light-guides for control diagnostics (Alfeeli 2007; Ahrens 2001; Fernando 2005; Fielder Florous Gan al. Henschel Kimurai 2002; O'Keeffe Reichle Troska 2003). For related fusion installations requirements quite demanding because exposure (Campbell, Griscom, 1998; Hodgson, ITER Physics Expert Group on Diagnostics, 1999; Shikama, 2003; Zabezhailov, 2005): ionising radiation, high temperature, disturbances. One major drawbacks use ionizing radiation is development colour centres, which affect dramatically transmission UVvisible-NIR spectral ranges (Griscom, Karlitschek, 1995). this reason, more than 30 years focus centres research (Friebele, 1976; Kaiser, 1974). Research induced pure doped bulk silica materials has a long history over 50 (Weeks, 1956), but it still actual (Radiation effects, Devine 2000; Pacchioni 2000), new (optical waveguides, multiplexers, fiber lasers) continuously devised evaluated. Apart diversity investigated challenges presented irradiation such subjected. The complexity dynamics lead complementary methods individuate these (electron paramagnetic resonance: EPR, luminescence) besides