540 nm diode-pumped passively Nd:SSO/KTP green laser with a single-walled carbon nanotube saturable absorber

The fluorescence spectrum of the Nd:Sc2SiO5 (Nd:SSO) crystal is measured. The central wavelength of the fluorescence band is 1080.1 nm with a full width at half-maximum (FWHM) of 3.4 nm. By using a single-walled carbon nanotube saturable absorber as a passive Q-switcher, a diode-pumped passively Q-switched intracavity frequency doubling Nd:Sc2SiO5/KTP green laser operating at 540 nm is demonstrated for the first time. The maximum average output power is 0.89 W at an incident pump power of 11.8 W, corresponding to an optical conversion efficiency of 7.5% and a slope efficiency of 10.2%. At the same incident pump power, a minimum pulse width of 94.8 ns and a maximum peak power of 19.1 W can be obtained.