High-energy Q switched Yb-doped fiber laser based on a ternary layered structured Ti2AlC saturable absorber.

Ti2AlC is a kind of ternary layered structured ceramic metal compound, combining the advantages of both ceramic and metal. Herein, the saturable absorption performance of Ti2AlC at the 1-µm wave band is investigated. The Ti2AlC behaves with excellent saturable absorption, which has a modulation depth of 14.53% and a saturable intensity of 13.27 MW/cm2. An all-normal dispersion fiber laser based on the Ti2AlC saturable absorber (SA) is constructed. The repetition frequency of the Q switched pulses increased from 44 to 49 kHz as the pump power rose from 276 to 365 mW, and the corresponding pulse width decreased from 3.64 to 2.42 µs. The maximum output single Q switched pulse energy is as high as 169.8 nJ. Our experiments prove that the MAX phase Ti2AlC has potential as a low-cost, simple preparation, and broadband SA material. To the best of our knowledge, this is the first demonstration of Ti2AlC serving as a SA material achieving Q switched operation at the 1-µm wave band.