New garnet crystal potentially suited for mini-laser devices of 1.5-μm spectral range

In Er:doped crystals, the 1.5-μm (4I13/2–4I15/2) transition is of negligibly small intensity. To intensify this transition, the (Gd,Y)3(Ga,Sc)5O12 host crystal has been chosen as a basic medium. The single crystal garnet films with thickness up to 18-μm were grown using the method of liquid-phase epitaxy on Gd3Ga5O12 substrates. The 20-at.% maximal concentration of Er3+-ions was achieved without luminescence quenching. The up-conversion processes were neutralized by the addition of an Fe-ions sensitizer. At the same level of absorbed pumping power, the luminescence intensity at the 1.5-μm band for the Er:Fe:doped crystal was approximately one to two orders of magnitude higher than that for traditional content. Heavily doped crystals demonstrated broadening of the luminescence band up to 300 nm.