Stable and tunable multi-wavelength erbium-doped fiber lasers using saturable absorbent tungsten disulfide

Abstract

Abstract A multi-wavelength erbium-doped fiber laser using tungsten disulfide (WS2) as a nonlinear saturable absorber is proposed. The laser structure consists of a Lyot filter and a WS2 film in a ring cavity. The WS2 film attached to the end of the fiber jumper can suppress the mode competition phenomenon caused by erbium-doped fiber due to its good nonlinear optical properties. In addition, it can suppress mode contention and stabilize multi-wavelength output. The number of wavelengths can be tuned by adjusting the length of the polarization-maintaining fiber (PMF). In the Lyot filter, the PMF of 4, 8 and 12 m excite 5, 9 and 13 wavelengths with 1.38, 0.7 and 0.42 nm intervals, respectively. The experimental results show that in the range of 1528–1536 nm, the side-mode suppression ratio is 42 dB. After 60 min of continuous excitation, the output wavelength of the structure remains stabilization. It can be used as a light source in distributed sensing and wavelength division multiplexing systems.