▎ 摘 要
Large-area monolayer graphene, synthesized by chemical vapor deposition, was transferred to a 1-in. quartz substrate. The high-quality monolayer graphene has been subject to characterization of the nonlinear properties near 1 mu m and was successfully applied as saturable absorber for passive mode-locking of a femtosecond Yb:KLuW laser. The diode-pumped mode-locked Yb:KLuW laser was tunable around 1.04 mu m and delivered pulses as short as 160 fs. The maximum output power of 160 mW was demonstrated for 203 fs pulse duration. The mode-locked laser results are comparable to those demonstrated with the same laser gain medium using single-walled carbon nanotubes as saturable absorbers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4760265]