Radiation Monitoring with Radiosensitive Pure-Silica Core Ultra-Low Loss Optical Fiber

This article presents a new prospect for radiation detection exploiting the high radiation sensitivity of an ultra-low loss pure-silica core optical fiber (ULL-PSCF). This fiber exhibits very high transient X-ray radiation-induced attenuation (RIA) levels from UV to IR during irradiation while its RIA quickly returns to a low permanent level after irradiation. In this work, the RIA kinetics are investigated exposing the ULL-PSCF to multiple short irradiation runs at different dose rates. A pre-irradiation has been demonstrated to stabilize the response of the optical fiber and to make it even more appealing for radiation detection and monitoring. After this pre-irradiation treatment, the RIAs at 620 nm and 1310 nm in particular exhibit an ON/OFF behavior: the permanent RIA is nearly zero in-between irradiation and the transient RIA quickly increases up to dB/m level when the ULL-PSCF is exposed to X-rays. By varying the fiber length and adapting the interrogation setup, large ranges of doses and dose rates can be detected with this new class of optical fibers.