Fig. 4: Microwave synthesis using dark pulse microcombs.
From: Broadband microwave-rate dark pulse microcombs in dissipation-engineered LiNbO3 microresonators
a Experimental setup. PM: phase modulator; EDFA: erbium-doped fiber amplifier; PC: polarization controller; FBG: fiber Bragg grating; PD: photodetector; AOM: acousto-optic modulator; PNA: phase noise analyzer. b Evolution of comb power versus time. c Electrical beatnotes of dark pulse microcombs for 5 different laser-cavity detunings. d Single-sideband (SSB) phase noise of the repetition rates of the dark pulse microcombs and the pump laser. The contribution of the pump RIN to the phase noise is plotted as the gray dashed line. Inset: zoom-in view of the noise spectra near 100 kHz offset frequencies. The spurs induced by phase modulation and pump RIN are indicated.
