Fig. 4: Parametric frequency comb simulation including the effects of two-photon absorption and free carriers within the SCF.
From: All-fibre heterogeneously-integrated frequency comb generation using silicon core fibre
a Nonlinear loss induced by TPA and FCs as a function of average input power. b Free carrier density in the silicon core versus time (black), and the optical pulse train power versus time (red). Subsequent pulses in the 26 GHz pulse train increase the free carrier density before complete recombination can occur, reaching a steady state over several nanoseconds. c Simulated optical spectrum at the output of the SCF mixer, at 27 dBm and 32 dBm input power (top and middle respectively) and (d) at 32 dBm without free carriers. TPA is included in all three spectra, and insertion loss is neglected.
