Graphene saturable absorbers applications in fiber lasers

Two-dimensional materials are widely used in a variety of fields, such as medical treatment, industrial preparation, machining, etc. In this review, we have made a detailed description of the development of fiber lasers as well as the evolution of two-dimensional materials, especially graphene. In addition, we describe the optical properties of graphene and its preparations, for instance, chemical exfoliatio, liquid phase exfoliation, electrochemical technique, chemical vapor deposition, supercritical fluid exfoliation, and thermal exfoliation. Meanwhile, we also summarized several types of graphene saturable absorbers like all fiber, D-shaped, and optical deposition. Furthermore, we summarize the optical applications of fiber lasers based on graphene. Finally, we also take a look at the future perspectives of graphene and discuss the future applications of graphene in the field of optics. It is note worth that future fiber lasers will use more heterostructures or gas-solid mixtures to prepare saturable absorbers.