Multi-wavelength Erbium-doped Fiber Laser with Tunable Wavelength Spacing Topics: Lasers and Photonic Components; Optical Fiber Technologies In Proceedings of the 15th International Joint Conference on e-Business and Telecommunications - Volume 1 DCNET, ICE-B, OPTICS, SIGMAP and WINSYS: , 241-245, 2018 , Porto, Portugal