Er,Ce:Y3Al5O12 crystal properties under UV, VIS and IR radiation exposure

Spectral and kinetic properties of Er,Ce:Y3Al5O12 crystals with various concentrations of impurities are investigated under optical excitations at 445, 457, 532, 808 and 980 nm wavelengths. An essential contribution of Ce3+ sensitizer ions in the process of population inversion formation between the I-4(13/2) and I-4(15/2) levels of Er3+ ions in YAG matrix is revealed due to the fact that their dipole-allowed interconfigurational f-d transitions have intense absorption UV bands and there are effective channels of optical excitation energy nonradiative transfer to the Er3+ ions. As a result, significant increase in the optical excitation efficiency near 445 nm wavelength is achieved which is important precondition for generation realization near 1.5 mu m.