Transition Of Yb3 Research Articles

Dependence of the stimulated emission cross section of Yb<sup>3+</sup>on host glass composition

The stimulated emission cross section for the <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> F <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5/2</inf> → <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> F <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7/2</inf> transition of Yb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> has been determined from absorption and emission measurements of 41 different oxide, fluoride, and oxyfluoride glasses at 293 K. The effective peak cross sections for transitions to Stark levels above the ground state range from approximately 0.3 to 0.8 pm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The largest values occur in borate and phosphate glasses; the smallest values occur in silicate and low-refractive-index fluoride glasses. Radiative lifetimes calculated from integrated absorption spectra are also reported and range from 0.6 to 2.7 ms. Systematic variations in cross sections with changes in modifier ions can be used to tailor stimulated emission cross sections and fluorescence lifetimes.

Compensation of Trivalent Europium and Ytterbium Ions in Calcium Fluoride by Interstitial Hydride Ions

Hydrogen has been diffused into calcium fluoride crystals doped with Eu, Yb and other Rare Earths. The local mode absorption from H− ions has been measured before and after X- or γ-irradiations and a detailed study has been made of the new electronic transitions of Yb3+ ions near 1 μm which appear after the irradiation. It is concluded that for Eu and Yb dopings, RE3+—H−(i) pairs are produced which are thermally unstable. In CaF2:Yb crystals, a second centre involving two hydride ions has also been identified.