Single longitudinal mode fiber ring laser

In this work, a dual-wavelength fiber ring laser working on the SLM regime is proposed and experimentally verified. A proof-of-concept device has been tested employing high precision small-sized SLM fiber lasers to complement the feedback produced by a passive FBG. The ring laser output inherits the spectral benefits of its SLM seed lasers but maintaining some power-related properties of ring cavities. These spectral benefits can also be achieved for a single wavelength, simplifying the requirements regarding power equalization between different wavelengths to obtain the SLM regime. The experimental results exhibit a remarkably good wavelength stability and SLM operation of a fiber ring laser with several meters of cavity length, both with single and multi-wavelength configurations.