Comparative study on the acousto-optic Q-switched pulse performances of 1520 and 1560 nm lasers in Er:Yb:RAl3(BO3)4 (R = Y and Lu) crystals.

1520 and 1560 nm acousto-optic Q-switched pulse lasers with high peak power and narrow width were respectively realized in Er:Yb:RAl(3)(BO(3))(4) (R = Y and Lu) crystals end-pumped by a 970 nm diode laser. For Er:Yb:LuAl(3)(BO(3))(4) crystal, 1520 nm laser with 350 μJ energy, 32 ns width and 10.9 kW peak power, and 1560 nm laser with 520 μJ energy, 67 ns width and 7.8 kW peak power were respectively obtained at pulse repetition frequency of 1 kHz. For Er:Yb:YAl(3)(BO(3))(4) crystal, 1520 nm laser with 210 μJ energy, 45 ns width and 4.7 kW peak power, and 1560 nm laser with 380 μJ energy, 102 ns width and 3.7 kW peak power were respectively obtained at pulse repetition frequency of 1 kHz. Pulse performances of 1520 and 1560 nm lasers were compared and the narrower pulse width of 1520 nm laser was ascribed to the higher stimulated emission cross-section.