A Novel α-BaTeMo2O9 Acousto-Optic Switch for Generating Stable 639 nm Pulsed Laser

In this paper, an acousto-optic (AO) Q-switch based on α-BaTeMo2O9 (α-BTM) crystal is designed and further applied to generate a laser pulse at 639 nm for the first time. The α-BTM AO demonstrates large diffraction angle of 0.93° high efficiency 85% nm. experiment, maximum Q-switched output power 362 mW achieved repetition rate 30 kHz, under absorbed pump 3.60 W, corresponding slope 15.2%. With transmittance T = 3%, shortest Q-switching width 54.7 ns generated 1 kHz. Meanwhile, beam quality factor M2 above measured, presenting magnitude 1.14 both x y directions. Our findings indicate that could act as excellent switching device which may help explore potential applications in visible field.