Permanent photobleaching of blue luminescence with a maximum at ~390 nm in Ge-doped fiber preforms by exposure to the third harmonic (354 nm) of a Nd:YAG laser has been observed. The experimental results show that photodestruction of a germanium oxygen-deficient center can occur without photoionization.
© 1996 Optical Society of America
E. M. Dianov and D. S. Starodubov, "Efficient photobleaching of 390-nm luminescence in germanosilicate preforms by the third harmonic of a Nd:YAG laser," Opt. Lett. 21, 635-637 (1996)