Few-layered W 2 C nanosheets based on passively mode-locked fiber lasers

Here, few-layered W2C nanosheets and microfiber-based few-layered W2C-SA are fabricated by the magnetron sputtering deposition method. The third-order nonlinear optical responses of the prepared 2D W2C nanosheets are investigated by the Z-scan method with βeff and n2 determined to be −88.2 cm/MW and −1.112×10−13 m2/W, respectively, revealing its excellent nonlinear saturable absorption properties and optical modulation capabilities. In addition, by incorporating microfiber based few-layered W2C-SA into Yb-doped and Er-doped fiber lasers (YDFLs and EDFLs), the passively mode-locked operations at the central wavelength of 1035.1 and 1562 nm are realized, respectively. In addition, multi-soliton bound mode-locked operation in EDFLs with soliton pulses up to 36 is realized. Our results not only demonstrate the capability of few-layered W2C as a wideband optical modulator, but also provide a practical approach to explore soliton dynamics in fiber lasers.