Float zone growth and spectroscopic characterization of Tm:GdVO4 single crystals

Abstract Heavily Tm-doped (5–20 at%) GdVO 4 single crystals were successfully grown by the floating zone method. All the grown crystals had no cracks and no inclusions for any dopant concentration. Low-angle grain boundary-free crystals were easily grown along the [1 1 0] direction whereas the crystals grown along the [0 0 1] direction comprised a few low-angle grain boundaries. The formation of bubble inclusions was effectively suppressed by optimizing growth rates and rotation rates. The absorption coefficient around 800 nm was large enough for pumping with a laser diode of 808 nm, which is conventionally used for Nd lasers. Intensive emission was observed even above 1950 nm where the self-absorption could be neglected. The fluorescence decay time decreased from 2.1 to 0.5 ms with increasing Tm concentration but is long enough for laser oscillation.