Intra-Cavity Dispersion of Microresonators and its Engineering for Octave-Spanning Kerr Frequency Comb Generation

We present an analysis on intra-cavity dispersion of a micro-resonator. As an example, different dispersion sources of a silicon nitride microring resonator are identified and evaluated over a wide wavelength range. We also show the dispersion flattening technique based on a strip/slot hybrid waveguide structure can be used to tailor the intra-cavity dispersions. Octave-spanning Kerr frequency combs are numerically simulated using 2-D-FDTD. It is shown that 7.5-fs two-cycle cavity solitons can be generated, enabling ultrawide mode-locked Kerr combs, with improved comb spectral flatness.