Q-Switched Fiber Laser at $1.5~\mu$ m Region Using Ti3AlC2 MAX Phase-Based Saturable Absorber

Abstract

A Ti 3 AlC 2 MAX phase-based saturable absorber (SA) is successfully demonstrated to induce passive Q-switching in an erbium-doped fiber laser (EDFL) at the 1.5 μm region. The Ti 3 AlC 2 -PVA film is fabricated using the solution casting method and incorporated into the laser cavity which uses a 0.89 m long erbium doped fiber as the gain medium. Stable and self-starting Q-switched laser pulses are observed above a threshold pump power of 87.81 mW at a central wavelength of 1567.4 nm. The repetition rate is observed to increase from 24.07 kHz to 46.3 kHz, while the corresponding pulse width decreases from 5.0 μs to 0.99 μs over a pump power range of 108.9 mW to 244.5 mW. At the maximum pump power of 244.5 mW, the highest pulse energy of 102.7 nJ and the maximum output power of 4.75 mW are obtained. These findings demonstrated the feasibility of the Ti 3 AlC 2 MAX phase as an SA material with significant promise for photonic applications. This is also, to the best knowledge of the authors, the first report of a Ti 3 AlC 2 MAX phase-based SA for inducing passive Q-switching in an EDFL.