Concise and Robust All-Fiber Ultrafast Laser Mode-Locked by Nonlinear Multimode Interference

Abstract

Ultrafast fiber lasers achieved by passive mode-locking techniques have wide application potentials from fundamental research to industry applications. Recently, nonlinear multimode interference existed in multimode fibers is proved to provide fast saturable absorption and can be used for ultrafast laser generation, and is especially paid much attention owing to various advantages [1]. We report an all-fiber ultrafast laser mode-locked by a graded-index multi-mode fiber (GI-MMF) saturable absorber based on nonlinear multimode interference, with a super concise cavity configuration and robust laser operation.