Positive influence of Ce3+ on effective transfer Yb3+: 2F5/2→Ho3+: 5I6 in silica-germanate glass for mid-infrared applications

A 1.5 time enhancement of a 2.0 mu m emission was achieved successfully in Yb3+/Ho3+ doped silica-germanate glass with a 0.1 mol% Ce3+ addition, which possesses a larger emission cross section (4.43 x 10(-21) cm(2)). According to the measured absorption spectra, the Judd-Ofelt parameters and radiative properties were calculated and discussed. The energy transfer mechanisms existed in Ho3+, Yb3+ and Ce3+ ions were investigated based on absorption, upconversion and fluorescence spectra. Meanwhile, the decay profiles of several levels were measured to further examine the enhanced mid-infrared emissions. Moreover, a high energy transfer microscopic parameter (7.54 x 10- 40cm6/s) of Yb3+-> Ho3+ process was obtained when 0.1 mol% Ce3+ ions were introduced into the Ho3+/Yb3+ system. All results indicate that the Yb3+/Ho3+/Ce3+ tri-doped silica-germanate glass is a promising candidate material for improving the Ho3+ 2.0 mm fiber laser performance. (C) 2017 Optical Society of America.