Passive harmonic mode-locking in a monolayer graphene-based long cavity fiber laser with high pulse energy

摘要

Passive harmonic mode-locking fiber laser is experimentally demonstrated with high pulse energy and excellent signal-to-noise-ratio by employing monolayer graphene and multi-mode fiber. A repetition rate of 20.26 MHz corresponding to the 3rd harmonic mode-locking has been achieved, with a pulse duration of ~ 603 fs, and a high single-pulse energy of ～1.04 nJ. The spectral width of the pulses is found to be decreased with the increase of the harmonic order. Such a fiber laser is suitable for optical access network or material processing applications.