High-energy 3-μm Er:YAG and Er,Cr:YSGG lasers Q-switched with semiconductor saturable absorbers

We report a comparative investigation of the free-running operation and the passive Q-switching operation of Er:YAG and Er,Cr:YSGG lasers pumped by xenon flashlamps. In the free-running regime, the Er:YAG laser achieved an output pulse energy up to 0.86 J, resulting in a maximum average power of 14.92 W, while the Er,Cr:YSGG laser achieved a maximum output pulse energy of 1.49 J, with a maximum average power of 20.65 W. The Q-switching of Er:YAG and Er,Cr:YSGG lasers is achieved using a semiconductor saturable absorber mirror (SESAM) for the first time, to the best of our knowledge, with output pulse energies of 0.28 mJ and 0.12 mJ and pulse widths of 1.13 μs and 0.83 μs, respectively. The SESAM Q-switched 3-μm solid-state lasers shall contribute to the development of compact and robust high-energy mid-infrared pulsed laser sources for medical and industrial applications.