Cascaded Four-Wave Mixing in Nonlinear Yb-Doped Fiber Amplifiers

We experimentally demonstrated high-power yellow and near-infrared laser emissions by cascaded four-wave mixing in a nonlinear Yb-doped multimode fiber amplifier, generating 2.0 W at 830 nm and 0.35 W at 594 nm. Moreover, multiple cascaded four-wave mixing processes which generated supercontinuum covering more than four octaves from 398 to 1700 nm was also investigated in Q-switched mode-locking regime. The group velocity matching for pump and parametric waves as well as multimode fiber amplification promoted the cascaded nonlinear frequency mixing processes.