Fig. 4: Sideband generation and interference.
a–i Multichannel generation using a fixed microwave amplitude modulation frequency of ωAM/2π = 50 kHz and a variable pump phase modulation frequency ωPM/2π of 10 (blue), 50 (red) and 100 (black) MHz. The relative sideband amplitude decreases for increased ωPM because the pump light accesses velocity classes with decreased occupation. a–ii Zoomed-in data revealing AM sidebands flanking each of the central and SB PM peaks. b When the two modulation frequencies are equal, i.e. ωPM = ωAM, the PM and AM sidebands overlap and interfere. The relative phase difference Δϕ between the modulating waves controls the height of the correlated upper (■, blue) and lower (▲, red) generated sidebands. (b-i) The generated spectrum at zero relative phase. b–ii The relative power amplitude response of the peaks have a visibility of 97%, while the central peak (●, purple) is independent of the relative phase. The two SB amplitudes differ from each other by (π − 0.38) radians of phase. The dashed lines show independent fits to a cosine.
