Line narrowing and wavelength stabilization in a tunable Er-Yb fiber ring laser with an Er twin-core fiber

摘要

Abstract: We propose and demonstrate experimentally that an Er-doped twin-core fiber (ErTCF) can be employed as a tracking narrow-band filter in tunable fiber ring lasers for line narrowing and wavelength stabilization. The partial separation of the light paths for different wavelengths in the ErTCF coupler mimics the saturable absorption with inhomogeneous broadening. The slow erbium ion saturation dynamics prevents wavelength hopping while it enables the filter to track the operation wavelength when the laser is tuned. The operation of the deice is improved by utilizing the inherent filtering effect of a twin-core coupler. !7