EDFA-Based Multi-Wavelength Laser Using Tunable Filter and Delay-Interferometer for WDM Systems

In this paper, we propose a novel method to produce the multi-wavelength laser. The main idea is to form a fiber ring cavity by utilizing an erbium-doped optical fiber amplifier with the supplementary combination of a tunable filter and a delay-interferometer. With the assistance of the tunable bandpass filter capable of varying the wavelength selection, the designated mode can be produced to prompt the stable excitation for the quadra-wavelength laser. The generated multi-wavelength laser enjoys the major advantage of a regular topological spectrum shape that is formed by delay-interferometry. With such an advantage, the multi-wavelength laser can be readily adopted as the light source for the wavelength division multiplexing application in optical communications.