A Versatile Fiber Laser Delivering Dispersion-managed Soliton and Q-switched Pulse

In this work, we present a novel versatile fiber laser based on the scheme of bidirectional transmission, with a nonlinear optical loop mirror (NOLM) and a graphene-polyvinyl alcohol (G-PVA) as saturable absorbers (SAs), and demonstrate the generation of dispersion managed soliton (DMS) and Q-switched pulse simultaneously or respectively for the first time to the best of our knowledge. In counter-clockwise (CCW) direction, the G-PVA is acted as a slow SA and used for obtaining Q-switched pulse trains, the DMS is achieved in clockwise (CW) direction by using NOLM. The proposed fiber laser can be switched in three cases by simply adjusting attenuator (ATT), pump power and polarizer controllers (PCs): (I) Only DMS is obtained. (II) Only Q-switched pulse trains are achieved. (III) The DMS and Q-switched pulse trains are established simultaneously. This versatile laser enables to generate two kinds of pulse, which is a potential candidate in communication system and industrial applications.