Growth, Spectroscopy and Laser Operation of Tm 3+ , Li + -Codoped Ca3Ta 1.5 Ga 3.5 O 12 -Type Disordered Garnet Crystal

Calcium niobium gallium garnet (CNGG) crystals doped with thulium (Tm 3+ ) ions possess disordered structure leading to inhomogeneously broadened emission bands which makes them attractive for generation of ultrashort pulses at ~2 μm [1] . The actual composition of CNGG deviates from the stoichiometry and cationic vacancies are present to ensure charge compensation. They can be eliminated by codoping with univalent alkali cations (Li + , Na + ). The related calcium tantalum gallium garnet (CTGG) shows better thermal properties than CNGG [2] . Here, we report on the growth, spectroscopy and first laser action in a Tm 3+ ,Li + -codoped CTGG (Tm:CLTGG) crystal.