Energy transfer in Yb 3+:Er 3+:YLF

Abstract

Yb 3+ as codopant in Er 3+ doped laser hosts is interesting due to the broad absorption band and the high absorption cross-section around 940 nm wavelength in Yb 3+. We report on measurements to determine the cross-relaxation parameter W 1b for the energy transfer from excited Yb 3+ to ground-state Er 3+ and W a3 for the inverse process in LiYF 4 (YLF). The micro-parameters, describing the electric dipole-dipole interaction between a donor and an acceptor ion are determined for the normal and the inverse process. Furthermore, the micro-parameters for the energy migration between the Yb 3+-ions and between the Er 3+-ions are determined.