Transient and Steady-State Radiation Response of Phosphosilicate Optical Fibers: Influence of H₂ Loading

Origins of radiation-induced attenuation in pure-silica-core and Ge-doped optical fibers under pulsed x-ray irradiation

“…1 of Ref. 16. However, at earlier times, where most of the diagnostics have to operate, the RIA levels could be higher than in the P-doped optical fiber due to the generation of room temperature metastable defects with strong absorption levels.…”

“…However, at earlier times, where most of the diagnostics have to operate, the RIA levels could be higher than in the P-doped optical fiber due to the generation of room temperature metastable defects with strong absorption levels. [14][15][16][17] To overcome the complexity to study the fibers' response at the shortest times, it is possible to lower the irradiation temperature (LNT in our experimental conditions), thereby slowing down the decay kinetics of these metastable defects. Decreasing the irradiation temperature allows studying the RT metastable defect contribution (impacting at time <1 ms at RT) even with a temporal resolution around hundreds of milliseconds.…”

“…Decreasing the irradiation temperature allows studying the RT metastable defect contribution (impacting at time <1 ms at RT) even with a temporal resolution around hundreds of milliseconds. The PSC OFs have been investigated in similar experimental conditions, 16,[18][19][20][21] highlighting the strong contribution of the STHs' related absorption bands 14,[20][21][22][23][24] and of chlorine impurities. 25,26 The Ge-doped OFs still deserve such investigation since they are the most used waveguides for telecommunications or sensing with fiber Bragg gratings thanks to their ultraviolet photosensitivity, related to the physics of GeX, Ge(1), and GLPC 14 defects.…”

Pulsed X‐Ray Radiation Response of Ultralow Loss Pure‐Silica‐Core Optical Fibers

“…Figure 1 shows the comparison between the RIA spectrum, 1 s after the X-ray pulse, of the ULL-SMF with the ones of canonical samples with other core compositions [21][22][23] measured under the same conditions at RT (Figure 1a) and LNT (Figure 1b) [24,25] : low OH PSC, Ge-and P-doped OFs. At RT (Figure 1a), as already observed in literature, [1,24,25] the P-doped fiber is the most sensitive to irradiation, just as the PSC and the Ge-doped fibers are the most tolerant, in the ms timescale after the X-ray pulse.…”

“…Figure 1 shows the comparison between the RIA spectrum, 1 s after the X-ray pulse, of the ULL-SMF with the ones of canonical samples with other core compositions [21][22][23] measured under the same conditions at RT (Figure 1a) and LNT (Figure 1b) [24,25] : low OH PSC, Ge-and P-doped OFs. At RT (Figure 1a), as already observed in literature, [1,24,25] the P-doped fiber is the most sensitive to irradiation, just as the PSC and the Ge-doped fibers are the most tolerant, in the ms timescale after the X-ray pulse. This is in accordance with the classification of the fibers' vulnerability under X-/γ-ray steady-state irradiation, where the P-doped fiber has RIA levels several orders of magnitude higher than the PSC and Ge-doped ones, which are comparable, over the whole investigated spectral range.…”