Figure 3: Non-interleaved phase-locked comb states.
From: Phase steps and resonator detuning measurements in microresonator frequency combs
(a–c) and (d–f) show experimental data for two more phase-locked microresonator comb states. Time domain traces in c and f are calculated on the basis of the measured spectral amplitudes and phases. The phases of the comb in a–c are aligned, except with the stronger modes (every 15 × FSR) having a relative phase of −ππ (black crosses). This leads to a nearly perfect suppression of the expected pulses at t=0 and t≈39 ps (cavity round-trip time). The phases of the comb state in d–f shows offsets of +π−π between adjacent sections and has a more complicated temporal structure with triplets of pulses emitted from the microresonator. Spectral amplitudes of this comb state show similarities to an inverted version of the comb in Fig. 2b.
