a, Thin-film lithium niobate microresonator Raman lasing suppression methods, including free spectral range (FSR) engineering and dissipation spectrum engineering (top and bottom panels, respectively). In the former, the microresonator FSR is ideally larger than the Raman gain bandwidth, and the Raman gain peak placed in between Raman modes, such that the effective Raman gain coefficient is reduced for Raman modes. In the latter, the microresonator is lossy at Raman mode frequencies, due to excess coupling between the microresonator and bus waveguide. Both methods maintain a critically coupled pump mode and increase the Raman lasing threshold, such that the Kerr parametric oscillation threshold may be lower. b, Entirely connected, octave-spanning dissipative Kerr soliton (DKS) frequency comb spectra from dispersion-engineered microresonators, utilizing the FSR engineering method (blue) and the dissipation engineering method (green).