1560-nm Acousto-Optic Q-Switched and Intracavity Frequency Doubling Laser Performances of ${\rm Er}{:}{\rm Yb}{:}{\rm RAl}_{3}({\rm BO}_{3})_{4}$ (${\rm R}={\rm Y}$ and Lu) Crystals

Abstract

Laser oscillations except for 1560 nm were suppressed and efficient acousto-optic Q-switched pulse lasers at a single wavelength of 1560 nm were realized in Er:Yb:RAl3(BO3)4 (R=Y and Lu) crystals by a special design of the cavity mirror transmissions, when a 970-nm diode laser with a 2% duty cycle was used as the pump source. At an absorbed pump power of 13.5 W and a pulse repetition frequency of 1 kHz, 400-μJ pulse energy with a width of 155 ns and 580-μJ pulse energy with a width of 110 ns were achieved in Er:Yb:YAl3(BO3)4 and Er:Yb:LuAl3(BO3)4 crystals, respectively. Furthermore, intracavity frequency doubling 780-nm Q-switched pulse lasers were realized by using a KTP nonlinear optical crystal. The pulse energy and width were 30 μJ and 80 ns for Er:Yb:YAl3(BO3)4 crystal and 50 μJ and 68 ns for Er:Yb:LuAl3(BO3)4 crystal, respectively.