Excimer-laser-induced spatially variant luminescence in pure-silica core fibers with fluorine-doped silica cladding

Optical fibers with pure silica cores of both low and high water content and fluorine-doped silica claddings were irradiated with 248 nm (KrF) excimer-laser radiation. In addition to the differences in the spectra of luminescent emissions of the respective cores, spatial variance was observed in the luminescence behavior across cross sections of the cores. Photographic evidence of this phenomenon is presented along with the corresponding luminescence spectra. Spectral correlations of the spatial variances are made, and the defects that are responsible for the luminescence are discussed.