Passively $Q$ -Switched Erbium-Doped Fiber Laser Based on Few-Layer MoS2 Saturable Absorber.

We demonstrate a passively Q-switched erbium-doped fiber laser (EDFL) based on few-layer MoS2 as a saturable absorber (SA). Few-layer MoS2 is prepared by the chemical vapor deposition method. The prepared MoS2 is transferred onto the end face of a fiber connector to form a fiber-compatible MoS2-based SA. The saturation intensity and modulation depth of the MoS2 SA are measured to be 0.43 MW/cm2 and 33.2%, respectively. The Q-switched EDFL has an all-fiber linear cavity with two fiber Bragg gratings as the end mirrors. By inserting the MoS2 SA into the laser cavity, stable Q-switched operation is achieved at 1.55 μm. The laser has a pump threshold of 20.4 mW, a pulse repetition rate tunable from 10.6 to 173.1 kHz, and a minimum pulse duration of 1.66 μs. Our results show that few-layer MoS2 is a promising SA for Q-switching laser operation. [ABSTRACT FROM PUBLISHER]