Steady-state characterization of up-conversion quenching in Er-doped glasses with the use of hypersensitive bands of ESA and GSA spectra

Abstract

A steady-state method was used for characterization of up-conversion quenching in Er-doped glasses. This method is based on measurement of pumping dependencies of quantum yield and the population of the 4 I 13/2 metastable manifold. The population was determined from absorption spectra variation under the pump of semiconductor laser. The feature of the method consists in measurement of absorption spectra variation in short-wave spectral range of 300 - 520 nm. In this spectral region, a hypersensitive excited state absorption (ESA) band (λ = 478 nm) for 4 I 13/2 → 4 G 9/2 transition was detected. The following parameters characterizing absolute intensity of ESA band were determined: line strength, integral cross-section, cross-section in maximum, and oscillator strength. This band was used for evaluation of the population of the 4 I 13/2 metastable manifold and up-conversion coefficients. The up-conversion coefficient, C up =1.7 ×10 -17 cm 3 s -1 , was obtained for an Er 3+ concentration of 6.8×10 20 cm -3 .