Dual-wavelength passively Q-switched Tm:YAP solid state laser based on Bi2Te3 nanowire saturable absorber

A kind of uniform Bi2Te3 nanowires was successfully synthesized by a facile hydrothermal method. And it was firstly used as saturable absorber in a 2 mu m mid-infrared solid state laser, as far as we know. With a careful adjustment, a dual-wavelength passively Q-switching laser operation was realized at 1945 nm and 1979.2 nm respectively. A maximum output power of 1.015 W was achieved, corresponding to the maximum single pulse energy of 3.965 mu J and peak power of 11.765 W. The shortest pulse width of 337 ns was obtained at a maximum repetition rate of 260 kHz. Compared with other popular saturabe absorbers in 2 mu m solid state laser, this material showed a better modulation capability to some extent. These results suggest that Bi2Te3 nanowire may be developed as another kind of promising nanomaterial for mid-infrared solid state pulse laser.