Passive Q-Switching of an All-Fiber Laser Using WS 2-Deposited Optical Fiber Taper

We demonstrate the passive Q-switching operation of an erbium-doped fiber laser using a few-layer WS
₂
-based saturable absorber with evanescent field interaction. WS
₂
flakes have been synthesized via a liquid-phase exfoliation method, and an optical fiber taper was selected as a light-material template that causes to achieve a long interaction length of the evanescent wave. Subsequently, the prepared solution was optically deposited around the 3-mm interaction length of the fabricated optical fiber taper with a 5-μm waist diameter. The proposed Q-switched fiber laser based on the WS
₂
-deposited fiber taper saturable absorber could generate stable output pulses at 1565 nm, with a pulsewidth ranging from 1.3 to 3 μs and a repetition rate of 33-108 kHz.