Actively Q-switched Nd:YLF laser emitting at 908 nm

Abstract

An actively Q-switched quasi-three-level Nd:YLF laser emitting at 908 nm, for the first time to our knowledge, was demonstrated. A RTP double-crystal scheme was used to realize electro-optical Q-switcher, and a L-shaped cavity structure was designed to suppress parasitic oscillation at 1047 nm. An 806 nm laser diode was used as the pump source with about 480 μs pulse width. With 46.4 mJ pump pulse energy input at repetition rate of 100 Hz, maximum output pulse energies of 0.84 mJ and 0.73 mJ were obtained with output transmissions of 6.5% and 11%, respectively. The corresponding peak pulse powers were up to 14.3 kW and 12.1 kW, and the output pulse widths were 58.6 ns and 60.3 ns. The central laser wavelengths were both at 908.3 nm with spectral bandwidth of over 0.7 nm.

486 nm pulsed Nd:YLF laser with intracavity sum-frequency mixing

“…The 45 • mirror, which was inserted at 45 • relative to both of the beam axes, was HR coated at 908 nm, and AR coated at 1047 nm. In the L-shaped cavity, the 45 • mirror can effectively suppress parasitic oscillation at 1047 nm [12], which has the maximum stimulated emission cross section in Nd:YLF crystal [10]. The transmissions of the output coupler (OC) were 8% at 908 nm, 62% at 1047 nm, and 96% at 486 nm.…”