The Yb3+ to Er3+ energy transfer in YAl3(BO3)4 crystal

The Yb3+ to Er3+ energy transfer in yttrium aluminum borate (YAB) crystal is investigated with the rate equation without considering the back energy transfer. The energy transfer coefficients (W25) in the crystals with different Yb3+ concentrations are determined and compared with those in other crystals. The transfer efficiencies and the micro-parameters of energy transfer and migration are also determined. The results show that the energy transfer from Yb3+ to Er3+ in YAB crystal is very efficient and the Yb3+–Er3+ co-doped YAB crystal may be a good candidate for the 1.55 μm laser media.