High efficiency actively Q-switched Ho: YVO 4 laser pumped at room temperature

A compact continuous wave and actively Q-switched Ho: YVO 4 laser pumped by a 1.94 μ m Tm: YAP laser is demonstrated. The maximal output power of 4.32 W at 2052.9 nm in a continuous wave regime is obtained at an absorbed pump power of 18 W, corresponding to the slope efficiency of 32%. For Q-switch operation, 3.93 W output is achieved at a pulse repetition frequency of 9 kHz with a minimum pulse width of 21.3 ns at 2051.9 nm, corresponding to the slope efficiency of 30.9%. In addition, different pulse repetition frequencies of Q-switch operation with 9, 10, 20, 30, 40 and 50 kHz were investigated comparatively. Furthermore, this is the first time an experiment on the actively Q-switched Ho: YVO 4 laser has been published.