The role of charge transfer processes for the induced optical losses in ytterbium doped fiber lasers

In this paper we present how charge transfer processes influences the induced optical losses (photodarkening) in ytterbium doped fiber lasers. The location of the charge transfer absorption band is strongly composition dependent and is correlated to the valence stability of the ytterbium ion in the silicate glass matrix. An improved photodarkening performance can in general be observed for a charge-transfer band shifted to shorter wavelengths, although other routes are also possible to reduce photodarkening. Other parameters that affect the laser performance, such as absorption and emission cross section, must also be considered.

[1]  G. Blasse.  On the Eu3+ Fluorescence of Mixed Metal Oxides. IV. The Photoluminescent Efficiency of Eu3+‐Activated Oxides , 1966 .

[2]  Mikko Söderlund,et al.  Photodarkening in large mode area fibers , 2006 .

[3]  Cesar Jauregui,et al.  94 W 980 nm high brightness Yb-doped fiber laser. , 2008, Optics express.

[4]  F. Cotton,et al.  Progress in Inorganic Chemistry Vol I , 2011 .

[5]  Deborah P. Partlow,et al.  Optical studies of biaxial Al-related color centers in smoky quartz , 1986 .

[6]  Christian Pedrini,et al.  Electronic processes in rare earth activated wide gap materials , 2005 .

[7]  U. Röpke,et al.  Power-law dependence of the photodarkening rate constant on the inversion in Yb doped fibers. , 2009, Optics letters.

[8]  Johannes Kirchhof,et al.  Photodarkening in Yb-doped silica fibers: influence of the atmosphere during preform collapsing , 2008, SPIE LASE.

[9]  Yoann Zaouter,et al.  High power ytterbium-doped rod-type three-level photonic crystal fiber laser. , 2008, Optics express.

[10]  F. Laurell,et al.  Improved photodarkening resistivity in ytterbium-doped fiber lasers by cerium codoping. , 2009, Optics letters.

[11]  G. Blasse.  Rare earth spectroscopy in relation to materials science , 1992 .

[12]  Magnus Engholm,et al.  Reduction of photodarkening in Yb/Al-doped fiber lasers , 2008, SPIE LASE.

[13]  R. Windeler,et al.  Effect of heat and H2 gas on the photo-darkening of Yb+3 fibers , 2006, 2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference.

[14]  T. Cardinal,et al.  Temporal evolution of photodarkening and successive photobleaching of an Ytterbium-doped silica double-clad LMA fiber , 2007, 2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference.

[15]  Andries Meijerink,et al.  Charge transfer luminescence of Yb3 , 2000 .

[16]  Jesper Lægsgaard,et al.  Dissolution of rare-earth clusters in SiO2 by Al codoping: A microscopic model , 2002 .

[17]  G. Blasse.  The ultraviolet absorption bands of Bi3+ and Eu3+ in oxides , 1972 .

[18]  D. Åberg,et al.  Strong UV absorption and visible luminescence in ytterbium-doped aluminosilicate glass under UV excitation. , 2007, Optics letters.

[19]  A. G. Petrosyan,et al.  X-ray-excited charge transfer luminescence in YAG:Yb and YbAG , 2001 .

[20]  L. Norin,et al.  Preventing photodarkening in ytterbium-doped high power fiber lasers; correlation to the UV-transparency of the core glass. , 2008, Optics express.

[21]  S. Unger,et al.  Photodarkening in Yb doped fibers: experimental evidence of equilibrium states depending on the pump power. , 2007, Optics express.

[22]  H. E. Hoefdraad.  The charge-transfer absorption band of Eu3+ in oxides , 1975 .