Spacing-adjustable multi-wavelength erbium-doped fiber laser using a fiber Michelson interferometer

We demonstrate a stable spacing-adjustable multi-wavelength erbium-doped fiber laser by employing an adjustable fiber Michelson interferometer. The central wavelength of the multi-wavelength laser can be tuned by adjusting the polarization controllers, while the wavelength spacing can be continuously tuned by adjusting the optical delay line in the Michelson interferometer. Tunable wavelength spacing is achieved in the range of 0.045 to 0.7 nm. More than 60 wavelengths within a flatness of 3 dB and wavelength spacing of 0.0474 nm can be achieved.