▎ 摘　　要

NOVELTY - A graphene-based saturable absorber comprises drip coating medium and graphene oxide film. The graphene oxide film is coated on the surface of the drip coating medium. The thickness of graphene oxide film is 1-20 nm. The drip media is made of quartz glass, K9 glass, K7 glass, or calcium fluoride glass. USE - Graphene-based saturable absorber (claimed). ADVANTAGE - The graphene-based saturable absorber has extremely fast saturable absorption characteristics and fast recovery time. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) production of saturable absorber, which involves adding graphene oxide into water or organic solvent, ultrasonically dispersing to prepare graphene oxide dispersion, applying graphene oxide dispersion droplets to the quartz glass surface, and drying. The concentration of graphene oxide dispersion is 0.2-2 mg/ml; and (2) usage of graphene-based saturable absorber for preparation of mode-locked laser.