Linearly Polarized 1180-nm Raman Fiber Laser Mode Locked by Graphene

In this paper, we demonstrate a linearly polarized 1180-nm passively mode-locked Raman fiber laser using graphene-based saturable absorber (SA). The pump source is a linearly polarized ytterbium-doped fiber laser at 1120 nm. Stable nanosecond mode-locked pulses with a repetition rate of 0.4 MHz are generated. The combination of Raman technology and the graphene-based ultrawide bandwidth SA offer a prospect of real wavelength-versatile mode-locked laser source. The mode-locked laser operating at 1180 nm is suitable for frequency doubling to yellow light after amplification.