Neutron testing of high-power optical fibers

Abstract

A selection of commercially available high-power optical fibres have been characterised for radiation susceptibility in Sandia's Annular Core Research Reactor (ACRR). The fibres were subjected to a total gamma and neutron dose >2 Mrad(Si) in a 7 ms pulse. The neutron fluence was >10 15 n/cm 2 . Changes in the transmission characteristics of optical fibres carrying high energy, short duration laser pulses (power densities of around 1.5 GW/cm 2 ) were measured.All fibres survived at least two consecutive radiation exposures, showing typical transient transmission losses of around 20%. Post radiation exposure, the transmission characteristics returned to those of pristine fibres within one minute.