Passive Q switching of Yb:CNGS lasers by Cr^sup 4+^:YAG and V^sup 3+^:YAG saturable absorbers

Trigonal langasite-type ordered silicate crystal [Math Processing Error]Yb:Ca3NbGa3Si2O14 (Yb:CNGS) is a promising material for efficient [Math Processing Error]∼1 μm lasers. We report on the first passively [Math Processing Error]Q-switched Yb:CNGS laser using [Math Processing Error]Cr4+:YAG and [Math Processing Error]V3+:YAG saturable absorbers (SAs) with a 976 nm volume-Bragg-grating-stabilized diode as a pump source. The laser crystal was a [Math Processing Error]c cut 3 at.% Yb:CNGS grown by the Czochralski method. It was placed in a compact microchip-type laser cavity. With a [Math Processing Error]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 [Math Processing Error]Q switching conversion efficiency of 90%. With the [Math Processing Error]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 [Math Processing Error]Yb:CNGS/Cr4+:YAG was numerically modeled showing a good agreement with the experiment.