High-brightness acousto-optic Q-switched 532 nm laser coupled with 200 μm fiber

We have developed a diode side pumped intracavity frequency switched Nd:YAG laser with fiber coupled output, which has the characteristics of high power, high beam quality and high brightness, and has a unique application in the field of laser processing. In order to solve the influence of thermal effect of Nd:YAG crystal on optical resonator, the thermal focal length was measured and a stable cavity structure was designed. When the repetition rate was 10 kHz, the maximum output power of the 532 nm laser was 96 W, and the pulse width was 55.8 ns. The beam quality was measured as M x 2 = 5.98 in the horizontal direction and M y 2 = 8.14 in the vertical direction, corresponding to the brightness of 6.97×10 8 W·cm −2 ·Sr. The maximum fiber coupling output power was 94 W, with a fiber core of 200 μm and a fiber coupling efficiency of 98 %. As far as we know, the fiber–solid-state acousto-optic Q-switched 532 nm laser obtains the highest brightness.