Graphene Mode Locked Fiber Laser at 2.8 \mu \text{m}
Mid infrared erbium (Er<sup>3+/sup> doped ZrF<sub>4</sub> BaF<sub>2</sub> LaF<sub>3</sub> AlF<sub>3</sub> NaF fiber laser mode locked by multilayer graphene saturable absorber was demonstrated. Mode locked pulses at 2.8 mm with an average output power of 18 mW at a repetition rate of 25.4 MHz, corresponding to a pulse energy of 0.7 nJ, were obtained. The pulsewidth was measured to be ~42 ps by a home made autocorrelator. Our experiment has validated the mode locking capability of graphene in the 3 mm wavelength region.
IEEE Photonics Technology Letters