Abstract
Based on an analog of electromagnetically induced transparency (EIT) in microfiber knot resonators with a two-ring parallel connection structure, a wide bandwidth and zero-dispersion slow-light waveguide is proposed. The EIT-like transmission spectrum with the variation of wavelengths for different coupling coefficients is numerical simulated. By appropriately adjusting the coupling coefficients of the two knot rings, a group time delay of about 72.4 ps with a flat wavelength bandwidth of about 82.7 pm and a full width at half-maximum of about 228 pm at one of the induced transparency windows is achieved theoretically. And the group time delay dispersion at the same induced transparency window nearly reaches to zero with a wavelength bandwidth of about 82.7 pm.