Single frequency fiber laser base on MXene with kHz linewidth

Abstract

MXene, as a novel two-dimensional (2D) material saturable absorber (SA), has excellent nonlinear optical characteristics and strong photo-materials interactions. Ti₂CT_x (T represents O, –OH or –F) nanosheets are a novel member of the MXenes and have been widely applied in photonics. In this paper, we studied the morphologies and the nonlinear optical properties of few-layer Ti₂CT_x (T represent O, –OH or –F) nanosheets. Then, we demonstrated a stable single frequency fiber laser (SFFL) based on a linear cavity with a loop mirror and this material was used as a SA. The SFFL has a central wavelength of 1549.68 nm and is amplified by an erbium-doped fiber amplifier (EDFA). The linewidth of this SFFL was measured and found to be approximately 1.3 kHz, which is the narrowest obtained for a SFFL based on this structure, and the signal-to-noise ratio (SNR) was 38.29 dB. The highest output power reached 32 mW and the power fluctuation of the oscillator and amplified laser were 1.8% and 7.1%, respectively.