To accomplish single-longitudinal-mode (SLM) output and continuous wavelength selection, an erbium-doped fiber (EDF) quad-ring (QR) laser is presented and experimentally examined. The designed QR scheme can induce a mode-filter effect to compress dense multi-mode oscillation, narrow laser linewidth and flatten power output simultaneously. Hence, the attained optical signal to noise ratio (OSNR) and output power are between in an obtainable tunability bandwidth of 1524.0 to 1569.0 nm. In addition, the observed output characteristics of stability, flatness and linewidth of the fiber laser are also investigated and discussed.
- Erbium-doped fiber laser (EDFL)
- Quad-ring (QR)
- Single-longitudinal-mode (SLM)
- Vernier effect