Spectroscopic properties of Tm, Ho： LiLuF4

LiLuF4 single crystals co-doped with thulium (5%) and holmium (0.5%), having large size, intact shape, and high optical quality, are successfully grown by the Czochralski technique. Absorption and fluorescence spectra of the crystal are measured. The absorption spectrum shows that the main absorption band locates at near 686 and 792 nm and the fluorescence spectrum peaks at 2.05 µm. At room temperature, the as-grown Tm, Ho: LiLuF4 single crystals are end-pumped by a fiber-coupled laser diode system with pumping wavelength of 795 nm under CW operations. A power of 50 mw continuous laser output at 2.05 µm wavelength is achieved. Meanwhile an obvious green light is detected.