Room-temperature near-infrared tunable laser operation of Cr(4+):Ca(2)GeO(4)

Large crystals of highly doped Cr(4+):Ca(2)GeO(4) were grown by a top-seeded solution growth method. Absorption and emission measurements for various crystal orientations have been performed. From the spectroscopic measurements, the only optically active center was identified as tetrahedrally coordinated Cr(4+). Gainswitched, tunable laser operation of Cr(4+):Ca(2)GeO(4) crystal was demonstrated. Pulse energies of 0.4 mJ at 1.4 microm have been generated at a repetition rate of 100 Hz. Tunability over the 1348-1482-nm spectral range has been demonstrated.