Wideband saturable absorption in few-layer molybdenum diselenide (MoSe2) for Q-switching Yb-, Er- and Tm-doped fiber lasers

摘要

We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorberby embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymerfilm. The MoSe2-polymer composite is used to Q-switch fiber lasers based onytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains ofmicrosecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nmand 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgapsaturable absorption in MoSe2, which is explained in the context ofedge-states, building upon studies of other semiconducting transition metaldichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2to the growing catalog of TMDs with remarkable optical properties, which offernew opportunities for photonic devices.