CW and passive Q-switching of 1331-nm Nd:GGG laser with Co2+:LMA saturable absorber.

In this paper, the output performances at 1331 nm in continuous-wave (CW) operation and the passive Q-switching regime of a Nd:Gd3Ga5O12(Nd:GGG) laser crystal have been investigated under pumping with diode lasers. A maximum CW output power of 1.5 W was reached at an incident pump power of 7.5 W; the overall optical-to-optical efficiency and the slope efficiency with respect to the pump power were 21.5% and 19.4%, respectively. The passive Q-switching regime was achieved with Co2+:LaMgAl11O19 (Co2+:LMA) saturable absorber (SA) crystals. A maximum average output power of 183 mW was recorded with a Co2+:LMA SA with initial transmission Ti of 90%. The pulse energy was 18.7 μJ and the pulse duration was 26.1 ns, which correspond to a pulse peak power of 0.7 kW. With a Co2+:LMA SA with Ti=81%, the average power decreased to 131 mW. However, the pulse energy increased to 21.4 μJ, the pulse duration was 16.4 ns and the pulse peak power increased to 1.3 kW. [ABSTRACT FROM AUTHOR]