A model for the population dynamics of in tellurite glasses with high erbium concentrations is proposed. Luminescence decay curves from transitions of and were measured experimentally. Upconversion coefficients were obtained by numerically solving the rate equations of the model to fit the population dynamics of the and levels. The upconversion coefficient for is found to be cm3/s and for is cm3/s. The model provides a good basis for explaining the experiment data because it shows a high sensitivity to the input fitting parameters. This model can be used to analyze transition properties of ions in glass hosts, where various energy levels of and the transitions between them cannot be neglected. A discussion of upconversion coefficients in tellurite glass in comparison with those in silica, silicate, and phosphate glasses is presented with an explanation of the origin of the differences from the perspective of different glass structures.
© 2001 Optical Society of America
(160.5690) Materials : Rare-earth-doped materials
(250.4480) Optoelectronics : Optical amplifiers
(300.6280) Spectroscopy : Spectroscopy, fluorescence and luminescence
Yongdan Hu, Shibin Jiang, Gino Sorbello, Tao Luo, Yong Ding, Bor-Chyuan Hwang, Jung-Hwan Kim, Hyo-Jin Seo, and Nasser Peyghambarian, "Numerical analyses of the population dynamics and determination of the upconversion coefficients in a new high erbium-doped tellurite glass," J. Opt. Soc. Am. B 18, 1928-1934 (2001)