Generation of bright‐dark Q‐switched pulse pair in thulium‐doped fiber laser cavity with titanium aluminum carbide absorber

Abstract The proposed titanium aluminum carbide (Ti 3 AlC 2 ) film‐based saturable absorber (SA) for Q‐switching in thulium‐doped fiber laser (TDFL) cavity offers a cost‐effective and practical alternative to conventional SA materials such as graphene or semiconductor. The Ti 3 AlC 2 film was produced using a simple and low‐cost casting approach with polyvinyl alcohol as a binder. The SA was devised from the film using a sandwich‐structured fiber‐ferrule platform and integrated into a TDFL ring cavity. The generated Q‐switched pulses were stable and had a repetition rate of up to 20.82 kHz with a minimum pulse width of 3.167 µs and a maximum pulse energy of 58.12 nJ. The Q‐switched laser produced the bright‐dark pulse pair. These results demonstrate the potential of Ti 3 AlC 2 as a promising SA material for practical applications in the field of fiber lasers.