Correlation of the absence of the 630-nm band with the intensity of photobleaching of ionizing radiation-induced loss in undoped silica fibers at -55°C

A correlation is reported between the intensity of the 630-nm drawing-induced band in undoped silica-core fibers and the abatement of photobleaching by 865-nm light of ionizing radiation-induced loss at 865 nm following gamma-ray exposure at -55°C. At -55°C, undoped silica-core fibers, both low- and high-OH containing, and polymer and glass clad, show intense, 865-nm photostimulated recovery of ionizing radiation-induced loss near 865 nm when the 630-nm drawing-induced band is weak or not present. This photobleaching behavior contributed significantly toward the low induced loss demonstrated by these fibers during exposure, and their faster recovery after exposure at low temperature