Tm-doped fiber laser mode-locked by graphene-polymer composite
  We demonstrate mode-locking of a thulium-doped fiber laser operating at 1.94\mu m, using a graphene-based saturable absorber. The laser outputs 3.6ps pulses, with~0.4nJ energy and an amplitude fluctuation~0.5%, at 6.46MHz. This is a simple, low-cost, stable and convenient laser oscillator for applications where eye-safe and low-photon-energy light sources are required, such as sensing and biomedical diagnostics 
M. Zhang, E. J. R. Kelleher, F. Torrisi, Z. Sun, T. Hasan, D. Popa, F.   Wang, A. C. Ferrari, S. V. Popov and J. R. Taylor
cond-mat.mes-hall cond-mat.mtrl-sci physics.optics