Fully Switchable Multi-Wavelength Fiber Lasers Based on Random Distributed Feedback for Sensors Interrogation

In this paper, the experimental study and characterization of a novel real-time switchable multi-wavelength fiber laser has been carried out. Two different gain materials, such as a 50-km SMF and a 2.5-km DCF fibers were characterized and compared, respectively. The MWFL can generate any wavelength combination with an emission lines distance of 50, 100, and 200 GHz fitting the ITU grid specifications. By using both Er-doped fiber and Raman amplification, a ∼30-nm-wide lasing window at the C band can be utilized to create up to 30 different lasing wavelengths into the ITU Grid, that can be switched automatically and in realtime when desired. Utilization of such a laser for versatile interrogation of different sensing networks is also shown.