Stable Erbium-doped Fiber Laser Research Articles

Switchable and stable erbium-doped fiber laser using the reconfigurable Lyot ring filter with WS2 film

A novel switchable and stable erbium-doped fiber laser (EDFL) using the reconfigurable Lyot ring filter (RLRF) with tungsten disulfide (WS2) film is proposed and experimentally demonstrated. The principle of RLRF is that the interference of the polarized lights with phase differences produces a comb spectrum with obvious envelope and uniform fluctuation. The transmission spectrum of RLRF can be changed by adjusting the polarization controllers (PCs) in RLRF. In the experiment, the actual length of the polarization-maintaining fiber (PMF) is 4 m. By adjusting PC1 adjacent to PMF, 2 to 5 wavelengths can be switched. Adjusting PC2 in the ring can change the equivalent length of the PMF in RLRF. When the equivalent length is 8 m, 5 to 8 wavelengths can be switched with a wavelength interval of 0.68 nm. The nonlinear material WS2 film is used as a means to suppress mode competition in the laser cavity, and the fiber laser has a stable output. The switching of the proposed EDFL is simple and flexible, and can be used in wavelength division multiplexing (WDM) systems.