Effects of Neutron-Gamma Radiation on Fiber Bragg Grating Sensors: A Review

Fiber Bragg grating (FBG) sensing is currently one of the leading measurement technologies, but has made only minor inroads into nuclear diagnostics due, for the most part, to insufficient proof of survivability in these environments. This paper aims to review the current knowledge in this area, incorporating reviews of radiation-induced darkening of silica, shifts in Bragg peak, and changes to mechanical properties, while taking into account core/cladding chemistry, structure, and coating materials. In doing so, this review not only highlights the achievements of the scientific community up to the present, but more importantly, the key areas in which knowledge is still lacking and further concentrated investigation would be beneficial.