RESUMO
Trigonal langasite-type ordered silicate crystal Yb:Ca3NbGa3Si2O14 (Yb:CNGS) is a promising material for efficient â¼1 µm lasers. We report on the first passively Q-switched Yb:CNGS laser using Cr4+:YAG and V3+:YAG saturable absorbers (SAs) with a 976 nm volume-Bragg-grating-stabilized diode as a pump source. The laser crystal was a c cut 3 at.% Yb:CNGS grown by the Czochralski method. It was placed in a compact microchip-type laser cavity. With a Cr4+:YAG SA, very stable 62.2 µJ/4.4 ns pulses were achieved at a repetition rate of 22.5 kHz. The average output power was 1.40 W at 1015.3 nm, corresponding to a Q switching conversion efficiency of 90%. With the V3+:YAG SA, the pulse characteristics were 13.3 µJ/11.1 ns at a higher repetition rate of 68.4 kHz. The performance of the Yb:CNGS/Cr4+:YAG was numerically modeled showing a good agreement with the experiment.
RESUMO
A single-layer graphene saturable absorber is employed for passive Q-switching of an Er, Yb:GdAl3(BO3)4 (Er,Yb:GdAB) compact laser, representing the first Er-doped oxoborate laser Q-switched by graphene. This laser is based on a c-cut 1.8 at. % Er3+, 15 at. % Yb3+:GdAB crystal diode-pumped at 0.976 µm. It generates a maximum average output power of 360 mW at 1.55 µm with a slope efficiency of 23% (with respect to the incident power). Stable â¼1 µJ/130 ns pulses are achieved at a repetition rate of 400 kHz. This result represents, to the best of our knowledge, the shortest pulse duration ever achieved in bulk Er lasers Q-switched by 2D materials. Graphene is a promising material for generating nanosecond pulses at high repetition rates (MHz range) in Er-doped oxoborate lasers emitting in the eye-safe range at 1.5-1.7 µm.
RESUMO
Passive Q-switching of a compact Tm:KLu(WO(4))(2) microchip laser diode pumped at 805 nm is demonstrated with a polycrystalline Cr(2+):ZnS saturable absorber. This laser generates subnanosecond (780 ps) pulses with a pulse repetition frequency of 5.6 kHz at 1846.6 nm, the shortest pulse duration ever achieved by Q-switching of ~2 µm lasers. The maximum average output power is 146 mW with a slope efficiency of 21% with respect to the absorbed power. This corresponds to a pulse energy of 25.6 µJ and a peak power of 32.8 kW.