Nonradiative losses due to the 4I11/2–4I13/2 transition of the Er3+ ion in Y3Al5O12, Gd3Sc2Al3O12, Y3Ga5O12, Gd3Ga5O12, and CaF2 crystals

Intracenter energy losses at the ⁴I_11/2–⁴I_13/2 laser transition have been studied which result from the multiphonon nonradiative relaxation for Er³⁺ ions in a number of crystals with the garnet structure. It is shown that in the scandium-aluminum garnet these losses are twice lower than in the yttrium-aluminum garnet and in the gadolinium-gallium and yttrium-gallium garnets they are an order-of-magnitude lower. It may be explained by a lowering of frequencies of phonons which are active for the given transition due to growth of the mass of an ion which replaces Al³⁺ in the garnet lattice and it is confirmed by a stronger temperature dependence of quenching in the gadolinium-gallium garnet. Mixed scandium-aluminum and gallium garnets with a high Er³⁺ content are suggested to use as more efficient matrices for lasers emitting at the wavelength about 3 μ.