GaAs Q-switched Nd:CNGG lasers: operating at 4 F 3/2 → 2 I 11/2 and 4 F 3/2 → 2 I 13/2 transitions

The nonlinear absorption properties of GaAs were measured at 1.06 and 1.34 µm by the open aperture Z-scan technique in this paper. Based on a neodymium doped calcium niobium gallium garnet (Nd:CNGG) disordered crystal grown by the Czochralski method, passively Q-switched lasers with the conventional GaAs wafer as the saturable absorber were demonstrated, operating on the transitions of F → I and F → I . For the F → I transition, the laser operated at 1063 nm with a pulse duration of 546 ns and a repetition rate of 98.5 kHz. While for the F → I transition operating at 1340 nm, the minimum pulse width was 499.6 ns with the pulse repetition rate of 110.7 kHz.