Radiation Sensitivity of Long Period Gratings written in B-Ge doped fiber under proton irradiation at CERN

In this contribution, the response of a Long Period Grating (LPG) inscribed in a B/Ge co-doped optical fiber exposed to proton irradiation is presented for the first time to the best of our knowledge. The experiment was performed in the proton irradiation facility at the European Organization for Nuclear Research (CERN) and lasted 146 hours. A proton fluence of ~ 4.4×1015 p/cm$^2$ was applied during the experiment, corresponding to a total absorbed dose by the sample of ~ 1.16 MGy. From the on-line measurements, we evaluated a maximum radiation induced shift of ~ 44 nm and no saturation was observed at the maximal accumulated dose. A post-irradiation recovery shift of ~ 7 nm was measured after 7.5 days. Collected off- line results demonstrated that the LPG temperature sensitivity is not significantly affected by irradiation.