Sub-100 fs Yb:CALGO laser based on gold nanoparticles saturable absorber

An Yb:CALGO solid-state mode-locked laser based on gold nanoparticles saturable absorbers (GNPs-SAs) is realized with the output pulse width of sub-100 fs. In our work, GNPs are synthesized by the Turkevich methods with good uniformity. The GNP is employed as SA in the X-type resonator Yb:CALGO laser. The shortest pulse of 91 fs with the central wavelength of 1065.1 nm and a spectral width of 13 nm is obtained under the pump power of 800 mW. And the maximum output power and repetition rate are 51 mW and 96.82 MHz, respectively. To the best of our knowledge, this is the shortest pulse ever reported in all solid-state lasers by employing GNPs as the SA.