Fabrication and characterization of new Er-doped yttrium-scandium-aluminum garnet ceramics

Rare-earth-doped yttrium aluminum garnets (RE³⁺:YAG) are widely used in a variety of applications, including materials processing, remote sensing, free-space and underwater communications, laser particle acceleration, gravitational wave interferometers, inertial confinement fusion. Moreover, RE³⁺-doped YAG materials show strong prospects for quantum information storage and processing, as well as for biological imaging, due to their high-Q 4f - 4f optical transitions.

Here we report the fabrication and characterization of the Er:YAG and Er:YSAG ceramics for implementing analysis as an active medium for 1500 nm lasing. High erbium content yttrium aluminum garnet (Er:YAG) and yttrium scandium aluminum garnet (Er:YSAG) ceramics have been fabricated from Er:YAG and Er:YSAG powders, respectively. All ceramic samples belong to the garnet-type cubic structure (space group Ia3d) without any traceable impure phases. The surface of Er:YSAG has fine-grained and homogeneous texture. The YSAG ceramics are harder to scratch with the grinding powder particles. Including Sc³⁺ in the Er:YAG crystal structure leads to decreasing melting temperature and improving mechanical characteristics and elastic-plastic properties of the materials. Based on SEM EDS cross-section analysis of Er:YSAG ceramic samples it can be deduced that all chemical elements (Er, Y, Al, Sc, O) are homogeneous distributed between grains and boundaries.

The optical transmittance of ceramics is affected strongly by the including Sc³⁺ which leads to decreasing melting temperature of the ceramic powders and consequently decreasing amount of the pores and producing more homogeneous media. Changing Al³⁺ with lager Sc³⁺ ion leads to increasing ceramic transmittance up to 60% at about 1500 nm.