Efficient passively Q-switched Nd:YLF TEM00-mode laser at 1053 nm: selection of polarization with birefringence
The natural birefringence of the Nd:YLF crystal is utilized to achieve a reliable TEM00-mode linearly polarized laser at 1053 nm in a compact concave-plano resonator. The efficient selection of the polarization relies on the combined effect of the difference in diffraction angle for σ- and π-polarization of a wedged laser crystal and the alignment sensitivity of an optical resonator. We further employ a Cr4+:YAG saturable absorber to perform the passively Q-switched operation. At an incident pump power of 12 W, the maximum average output power is up to 2.3 W with a pulse repetition rate of 8 kHz and a pulse width of 9 ns. The pulse energy and peak power are found to be 288 μJ and 32 kW, respectively.