Interval-Adjustable Multi-Wavelength Erbium-Doped Fiber Laser With the assistance of NOLM or NALM

A novel interval-adjustable multi-wavelength erbium-doped fiber laser (EDFL) is experimentally demonstrated in this paper. The proposed EDFL is based on the cascaded structure of two-segment Sagnac filter and nonlinear optical loop mirror (NOLM). By properly adjusting the polarization controllers (PCs), the wavelength interval and number of output wavelengths can be changed. When the wavelength interval is 2nm and 0.5nm, the number of wavelengths is 1–3 and 5–8, respectively. At the same time, when the number of output wavelengths is 6~8, the wavelengths can be tuned within a certain range. In order to compare the effects of two similar nonlinear loop mirrors on the outputs, a nonlinear amplifying loop mirror (NALM) is used to replace the NOLM in the laser cavity. The number of output wavelengths is increased to 10 when using NALM. The structure and principle of NOLM and NALM are analyzed. The influences of the two structures on the stability and output power of the laser are also discussed.