Inkjet-printing of graphene saturable absorbers for ∼2 μm bulk and waveguide lasers

A technique for inkjet-printing of graphene saturable absorbers (SAs) for similar to 2-mu m bulk and waveguide lasers is presented. Based on distillation-assisted solvent exchange to fabricate high-concentration graphene inks, this technique is capable of producing few-layer graphene films of arbitrary shape. Absorption saturation of graphene printed on glass is demonstrated at similar to 1.56 mu m for picosecond and femtosecond pulses indicating a large fraction of the saturable losses. Inkjet-printed transmission-type graphene SAs are applied in passively Q-switched nanosecond thulium (Tm) microchip and planar waveguide lasers. The Tm microchip laser generates 136 ns / 1.2 mu J pulses at 1917 nm with a repetition rate of 0.37 MHz with a Q-switching conversion efficiency reaching 65%. The planar waveguide laser generates 98 ns / 21 nJ pulses at 1834 nm at a repetition rate in the MHz-range. The inkjet-printing technique is promising for production of patterned SAs for waveguide lasers. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.