Microfiber-coupler-assisted control of wavelength tuning for Q-switched fiber laser with few-layer molybdenum disulfide nanoplates.

Based on the liquid exfoliated method, we obtained the few-layer molybdenum disulfide (MoS2) nanoplates solution. By thermal evaporation method, we directly deposited MoS2 thin film onto the facet of a fiber patch cord. The modulation depth of the film is as high as 29%, and a Q-switched fiber laser was achieved. We also provided a new method to continuously tune the output laser with a tuning sensitivity of ∼5.5  nm/(1%  strain) by controlling the cavity loss with a strained microfiber coupler (MFC).