Open AccessInvestigation of photodarkening in tandem-pumped Yb-doped fibers
Author(s) -
J. S. Park,
T. H. Kim,
Y. J. Oh,
Eun Jae Park,
J. W. Kim,
Hoon Jeong
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.400094
Subject(s) - photodarkening , materials science , fiber laser , tandem , optics , silica fiber , laser , doping , ytterbium , optoelectronics , optical fiber , fiber , wavelength , physics , composite material
Investigation of photodarkening (PD) in Yb-doped fibers tandem-pumped at 1018 nm is reported. For a homemade Yb-doped aluminosilicate double-clad fiber (YADF), the transmitted power of a 633 nm probe beam is reduced by 2.4% over 2 hours for the tandem pumping configuration at 1018 nm, which is significantly smaller than 33.3% for a laser diode (LD) pumping at 976 nm. A tandem-pumped Yb fiber amplifier also shows a much smaller decrease in the amplified output power over time than a LD-pumped Yb fiber amplifier. Based on fluorescence spectra of the YADF, we can not only associate PD of the YADF to intrinsic oxygen deficiency centers or Tm 3+ impurities but also confirm the impact of the excited Yb 3+ ion density on PD. The benefits of the tandem pumping in a high-power Yb fiber laser system will be discussed.