Abstract
We studied on a method needed to generate mode-locked microcomb in a silica toroidal microcavity. By
controlling the input power and wavelength, we obtained microcombs with arbitrary free-spectral range.
We also developed a Lugiato-Lefever equation including Raman scattering effect and investigated the
influence of Raman scattering upon microcomb formation. A bandwidth ranging from 1550 to 2200 nm
was obtained experimentally from a continuous-wave pump due to broadband Raman gain of silica.
