Transient light induced grating study of excitation diffusion in Y3Sc2Ga3O12 laser crystals

摘要: Abstract Excitation migration over the lower energy levels in Y3Sc2Ga3O12 (YSGG) laser crystals doped with Cr, Er, Tm, and Ho ions was studied using two-wave mixing light induced grating (LIG) technique. The results of LIG measurements were compared to data obtained from luminescence kinetics spectra overlap studies migration. comparison three different spectroscopic techniques allowed more detailed analysis complicated pattern transfer processes than any one method alone. found be very efficient, especially highly crystals. diffusion coefficients determined direct much higher those calculated dipole-dipole approximation absorption emission spectral measurements. This implies stronger coupling between interacting ions. In Tm a surprisingly strong increase efficiency concentrations 8 × 1020 cm−3 1.5 1021 observed both experiments. too cannot explained terms low multipolar transfer. Exchange percolation model are discussed as possible explanations for experimental results.