Comparisons of kilowatt Yb-Raman fiber amplifiers employing a superfluorescent fiber source and fiber oscillator

In this paper, we demonstrate experimental investigations on kilowatt-level Yb-Raman fiber amplifiers (YRFAs) employing a superfluorescent fiber source (SFS) or a multi-longitudinal mode fiber oscillator (OSC) as the Raman-pump laser. Through comparing the output properties of the two YRFAs, the experimental results reveal that the YRFA employing the SFS is superior to the YRFA employing the OSC in the performances of power scalability and narrow-linewidth operation. Meanwhile, about 1.16 kW Raman-signal laser at 1120 nm is obtained through the YRFA employing the SFS as the Raman-pump laser. Overall, the presentation could provide an effective solution for the design of high-power narrow linewidth YRFAs.