Determination of the effective upper laser level lifetime from an end-pumped Tm,Ho:YLF laser

We report the measurement of the effective upper laser level lifetime from an end-pumped Q-switched Tm,Ho:YLF laser. When the pump power is 1.58 W, the effective upper laser level lifetime is only 2.5 ms, which is less than the fluorescence lifetime (∼16 ms) of the upper laser level. The dependences of the effective upper laser level lifetime on the pump power and the temperature of laser crystal are firstly obtained experimentally. The experimental results show that the effective upper laser level lifetime decreases with increasing the pump power and the temperature of laser crystal, respectively. Furthermore, the experimental results are compared with the theoretical results.