Fig. 5: Sidemode spectra of the output optical field.

a–d Spectra of excited sidemodes that are closest to the right of the center mode. e–h Spectra of excited sidemodes that are fourth closest to the right of the center mode. The figure corresponds to Combs 1 to 4 displayed in Fig. 2. The blue lines correspond to the noise contribution of pattern drift [the computation of Eq. (71)]. The green lines correspond to the noise contribution of pattern deformation [the computation of Eq. (76)]. The red lines correspond to the spectra obtained after the numerical simulation of the stochastic modal equations. These simulations clearly indicate that pattern drift noise dominates the spectra for low offset frequencies, while pattern deformation noise dominates the spectra for high offset frequencies.