463-MHz fundamental mode-locked fiber laser based on few-layer MoS_2 saturable absorber

We report on the passive-mode-locking operation of a fiber laser with a fundamental repetition rate of 463 MHz based on molybdenum disulfide (MoS2) saturable absorber (SA). By embedding MoS2 into polyvinyl alcohol (PVA) thin film, MoS2-PVA SA was prepared with a modulation depth of 2.7% and a saturation intensity of 137 MW/cm2. The mode-locked fiber laser-employed MoS2-PVA SA was achieved with center wavelength of 1556.3 nm, 3-dB bandwidth of 6.1 nm, output power of 5.9 mW, and an extinction ratio of up to 97 dB in the RF spectrum. The demonstration of mode-locking operation with high fundamental repetition rate and high spectral purity indicates that MoS2-PVA SA can be a good candidate for high-precision ultrafast applications.