880-nm-Diode-Laser-End-Pumped Electrooptically Q-Switched Nd:YLF Laser With High Energy and Good Beam Quality at 1047 nm and 1 kHz

An electrooptically Q-switched Nd:YLF laser end-pumped by an 880-nm laser diode with high energy and short pulsewidth at 1 kHz is demonstrated. The asymmetry of the focal lengths of thermal lens along the a-axis and c-axis is observed, and the cylindrical lens is used to compensate for the thermal lens effect along the a-axis. We experimentally studied the performance of the Nd:YLF laser with different combinations of the output coupler transmission T and the focal length f of cylindrical lens. With T = 40% and f = 300 mm, 9.5-mJ pulse energy, 9.5-ns pulsewidth, and beam quality factors of M
²
_x
= 1.74 andM
²
_y
= 1.97 are obtained. Moreover, the relationships between the pulse width and pump power as well as beam transverse mode were experimentally studied and discussed.