The optical absorption spectrum and the 400-nm photoluminescence (PL) of a 1.4-mol. % Ge photosensitive optical fiber preform subjected to high fluence of 193-nm ArF and 248-nm KrF excimer-laser irradiation are measured. The largest absorption increases occur near 200  nm in both cases, but a small net bleaching of absorption is obtained near the laser wavelength for KrF irradiations. The blue PL decreases during ArF exposure but increases with the KrF laser. In similarly excited 9-mol. % Ge fiber preforms the blue PL always decreases. A study of the PL intensity as a function of irradiating laser light intensity shows no evidence of multiple photon absorption effects.
Optics Letters
Department of Electronics

Albert, J, Allard, L.B., Brebner, J.L., & Atkins, G.R. (1997). Photoinduced optical absorption and 400-nm luminescence in low-germanium-content optical fiber preforms irradiated with ArF and KrF excimer-laser light. Optics Letters, 22(11), 819–821. doi:10.1364/OL.22.000819