Permanent photoinduced optical attenuation has been observed in Tm3+-doped aluminosilicate glass fibers on exposure to near-resonance mode-locked 1064-nm radiation at 300 K. The rate of this darkening was observed to follow a 4.7 ± 0.4 power dependence on the 1064-nm intensity. The result shows that absorption of infrared light of moderate intensity can lead to photoionization in rare-earth-doped glass, provided that a multiphoton stepwise excitation channel exists.
© 1993 Optical Society of America
Original Manuscript: January 11, 1993
Published: May 15, 1993
M. M. Broer, D. M. Krol, and D. J. DiGiovanni, "Highly nonlinear near-resonant photodarkening in a thulium-doped aluminosilicate glass fiber," Opt. Lett. 18, 799-801 (1993)