Dual-wavelength high-power Yb-doped double-clad fiber laser based on afew-mode fiber Bragg grating

摘要

We report a high-power dual-wavelength Yb-doped double-clad fiber laser based on a few-mode fiberBragg grating (FMFBG). The FMFBG was fabricated by using a piece of fiber in a length of fiber with acutoff wavelength of 1225 nm, which supported two modes at 1060 nm. The laser was pumped by afiber pigtailed laser diode working at 915 nm. Single-wavelength, dual-wavelength and triple-wavelength laser oscillations were observed when the fiber laser operated under different low pumppowers. However, stable dual-wavelength operation was achieved at higher pump power of 3.9 W andremained unchanged until the output power reached 5.67 W under the maximum available pumppower of 10.7 W. The laser wavelengths were centered at 1059.12 and 1060.80 nm with a full-width athalf-maximum of 37 and 43 pm, respectively. The signal-to-noise-ratio was greater than 50 dB and thebeam quality factor (M2) was about 1.9.