Broadband wavelength-tunable single-longitudinalmode erbium-doped fiber ring laser using saturable-absorber filter

In this paper, a broadband wavelength-tunable erbium-doped fiber (EDF) ring laser with single longitudinal mode (SLM) output achieving 82.6 nm lasing bandwidth from 1481.0 to 1563.6 nm is proposed and experimentally demonstrated. For the proposed laser scheme, the S- and C-band erbium-doped fiber amplifiers (EDFAs) in parallel structure are used to serve as the gain medium for broadband wavelength tuning. Furthermore, we use a saturable-absorber filter (SAF) inside the fiber cavity to serve as a narrow band filter to guarantee a SLM operation. Besides, the performance of output power, wavelength, side-mode suppression ratio (SMSR) and stability are also analyzed and discussed.