Laser-diode-pumped Tm:SrF single crystal for high efficiency CW laser operation at ∼2 µm.

A Tm:SrF single crystal is grown by a modified temperature gradient technique (TGT). A study of the fluorescence characteristics and laser performance is carried out. Under laser-diode (LD) end-pumping, a continuous-wave (CW) laser is demonstrated.

High-efficiency ∼2 µm CW laser operation of LD-pumped Tm:CaF single-crystal fibers.

The Tm:CaF single-crystal fibers were successfully grown by modified temperature gradient technique method. The J-O intensity parameters, spontaneous radiative transition rates, radiative lifetimes and fluorescence branching ratios of Tm were calculated with Judd-Ofelt theory. A systematic study of the fluorescence characteristics has been carried out.