High-Power Single-Longitudinal-Mode Fiber Laser With a Ring Fabry–PÉrot Resonator and a Saturable Absorber

We demonstrated a high-power single-longitudinal-mode (SLM) all-fiber laser. In the cavity, a fiber Bragg grating is used to select the appropriate wavelength at 1565 nm, and a fiber ring is incorporated to act as a Fabry-Perot resonator, which greatly reduces the longitudinal-mode density. Meanwhile, an unpumped erbium-doped fiber serves as a saturable absorber to ensure the SLM operation. Finally, a high-power SLM fiber laser producing as high as 867-mW output power has been experimentally demonstrated.