Diode-pumped efficient laser operation and spectroscopy of Tm,Ho:YVO4

Spectroscopic characterization of co-doped Tm,Ho:YVO4 crystal grown by the Czochralski method has been performed including absorption spectrum, emitting spectrum and luminescence decay lifetime. The polarization emitting spectrum around 2 μm is accomplished by exciting a singly Ho3+ doped YVO4 crystal to exclude the influence of Tm3+3F4–3H6 transition and the emission cross section is deduced from both Fuchtbauer–Ladenburg (F–L) equation and reciprocity method (RM). In addition, we report up to 10.4 W continuous wave (CW) output with a conversion efficiency of 40% and 10.3 W Q-Switch output with 12.5 kHz pulse repetition rate of diode-pumped cryogenic Tm,Ho:YVO4 laser. For Q-Switch operation, the minimum pulse width of 28.2 ns is obtained, all of which demonstrate that the Tm,Ho:YVO4 is excellent laser material for 2 μm radiation.

Research highlights
► Tm,Ho:YVO4 crystal was grown by the Czochralski method.
► A number of spectroscopic measurements were performed on it.
► The spectrum indicates it is excellent laser material for 2 μm radiation.
► Up to 10.4 W continuous wave (CW) output was achieved under cryogenic temperature.
► For Q-switch operation we obtained 10.3 W output with 12.5 kHz pulse repetition rate.