Q-switched and noise-like mode-locked fiber laser based on ternary transition-metal carbide Nb2AlC saturable absorber

Abstract

The saturable absorption of layered ternary transition-metal carbide (MAX) Nb2AlC is investigated in this work. Nb2AlC-based saturable absorber (SA) device is prepared and applied in an Er-doped fiber laser (EDFL). The EDFL can generate Q-switched and noise-like mode-locked pulses based on the excellent Nb2AlC SA. The EDFL operates in a Q-switched pulses mode state when the pump power is up to a threshold value of 50 mW. For the Q-switched pulse, the maximum single pulse energy is 66 nJ. The laser pulse generation mode switches to a noise-like mode-locked state when the pump power increases to 170 mW. The coherent spike duration is 2.8 ps and the corresponding maximum single pulse energy is 1.5 nJ at a pump power of 439 mW. A preliminary review of available literature indicates no reports of layered ternary carbide Nb2AlC as SA in an EDFL to generate switchable laser pulse modes. Results of this study suggest that ternary MAX Nb2AlC can be a remarkable nonlinear optical (NLO) device to explore switchable laser pulse generation modes and can encourage further studies on the ternary transition-metal carbides.