Graphene-Assisted All-Fiber Optical-Controllable Laser

All-optical controlling provides the burgeoning, precise, and compact access in photonics and optoelectronics with tunable performance. Through tuning physical parameters of optical-controlled devices, such as effective index, bandwidth and dispersion, the output characteristics of free-running lasers can be manipulated for widespread applications in spectroscopy and laser biology. Among which the flexible optical-thermal tunability of graphene introduces an advantageous avenue for the enhancement of photosensitivity of optical-controlled devices to efficiently regulate laser properties. Here, we fabricate an optical-controllable fiber filter based on a graphene-assisted micro-fiber Bragg grating, whose wavelength can be linearly tuned by controlling pump light, and a tuning step of 3.1 pm is achieved. By cooperating it with a fiber laser operating at a Q-switched mode-locked state, the lasing wavelength is all-optically controlled with a linear tuning sensitivity of 23.5 pm/mW. Considering the optical controlling performances, such a wavelength-tunable fiber laser may find potential applications in all-optical computing, all-optical logic gating, and generation of microwave source.