Fig. 6: Phase noise spectra of the microwaves.

a–d Phase noise spectra of the microwaves with the lowest frequency. e–h Phase noise spectra of the microwaves with the fourth lowest frequency. The figure corresponds to the results obtained via photodetection of Combs 1 to 4 displayed in Fig. 2. The simulation results (redline) are obtained from the simulation of Eq. (1). The blue lines correspond to pattern drift noise [the computation of Eq. (81)] while the green lines correspond to pattern deformation noise [the computation of Eq. (86)]. The numerical simulations show that, as in the case of optical noise, pattern drift noise dominates the spectra for low offset frequencies, while pattern deformation noise dominates the spectra for high offset frequencies.