Optimization of stacking graphene layers as a saturable absorber for mode-locked lasers

The optimization of stacking graphene layers as a saturable absorber (SA) for achieving both wider dynamic range and shorter pulsewidth in mode-locked lasers (MLLs) is demonstrated. This study clearly shows an important conclusion that the lower stacking graphene layers, such as the 5-layer is preferable to use as SA for wider dynamic range and hence better pulse tunability range of 5.1-μW, whereas the higher stacking graphene layers, such as the 17-layer is preferable to use as a SA for providing stable and shorter pulsewidth of 523-fs.