Molybdenum disulfide saturable absorber for eye-safe mode-locked fiber laser generation

Abstract

We demonstrated an all-fiber mode-locked Thulium–Holmium co-doped fiber laser (THDFL) based on molybdenum disulfide (MoS2) tape saturable absorber. The THDFL generates a mode-locked pulse in anomalous regime at 1,979[Formula: see text]nm using 5[Formula: see text]m long Thulium–Holmium co-doped (THDF) as a gain medium. Through mechanical exfoliation method, the MoS2 was mechanically extracted from a commercial MoS2 crystal by using a clear scotch tape. Through balanced twin-detector measurement, the obtained MoS2 tape has a nonlinear absorption of 10% with 100[Formula: see text]MW/cm2 saturation intensity. Under 775[Formula: see text]mW to 852[Formula: see text]mW pump power, a stable pulse train was obtained at 9.12[Formula: see text]MHz repetition rate with a signal-to-noise ratio (SNR) of 45[Formula: see text]dB. The maximum output power and pulse energy were measured about 20[Formula: see text]mW and 2.2[Formula: see text]nJ, respectively. With a 3-dB spectral bandwidth of 2.1[Formula: see text]nm, the minimum possible pulse width was determined as 1.97[Formula: see text]ps.