Study of a Graphene Saturable Absorber Film Fabricated by the Optical Deposition Method

A film composed of graphene saturable absorber (GSA ) prepared for a passive mode-locking (PML) fiber laser is successfully fabricated by an optical deposition method. The parameters of the process of optical deposition, including the laser intensity, deposition time and concentration of graphene solution, are investigated. Characterization of the graphene saturable absorber film, such as the modulation depth, nonsaturable loss and saturable intensity, is performed based on theoretically and experimentally optimizing the technological parameters of optical deposition. By precisely controlling the parameters of optical deposition, a GSA film is fabricated to satisfy the requirement of the ultra-fast pulsed fiber laser.