▎ 摘　　要

A compact and efficient intracavity optical deposition of graphene saturable absorber (SA) for a passively mode-locked fiber laser is proposed and demonstrated. The setup for optical deposition is integrated in a fiber ring laser through a slot collimator. By dripping the dimethylformamide (DMF) solution of graphene into the gap of the slot collimator between two fiber ferrules, graphene can be well deposited onto the fiber end to form an SA. The transmission loss of graphene SA is measured. As for application, the fiber ring laser is passively mode-locked with the prepared graphene SA and generates a 1 ps, 13.6 MHz soliton pulse train. (c) 2012 The Japan Society of Applied Physics