Bulk crystal growth and thermal, spectroscopic and laser properties of disordered Melilite Nd:Ca2Ga2SiO7 single crystal

A large sized Nd-doped Ca2Ga2SiO7 single crystal was successfully grown by the Czochralski technique. The effective segregation coefficient of Nd3+ was measured to be 1.16. The thermal, spectroscopic and laser properties were systematically investigated. The thermal conductivity was found to increase with increasing temperature, exhibiting glass or alloy like behavior, and is inherently associated with the disordered structure of the Ca2Ga2SiO7 crystal. The polarized absorption and fluorescence spectra were measured at room temperature, and the spectrum parameters were calculated using the Judd-Ofelt theory. Furthermore, continuous wave laser operation at 1.06 μm along the crystallographic a- and c-axes was demonstrated. A laser output power of 430 mW with an optical conversion efficiency of 14.2% and a slope efficiency of 16.7% was achieved. These results show that Nd:Ca2Ga2SiO7 holds excellent promise for use as a disordered crystalline laser material.