Generation of orange pulse laser in waterproof fluoride glass fibre with graphene thin film

Orange laser pulses were successfully generated in a Pr-doped waterproof fluoride glass fibre (Pr:WPFGF) using a graphene thin film as a saturable absorber (SA). Two pulse generation modes were observed: a continuous mode with 0.47 mu s pulse duration with a 2.61 mu s repetition period and a single giant pulse mode with 9.7 ns pulse duration. The peak wavelength was 603 nm. This result shows that a graphene thin film can be effective as an SA in the visible region, and in the future a visible ultra-short pulse laser with a modelocking technique may be demonstrated.