"Phase Noise Analysis for Microwaves Generated with Kerr Optical Frequency Combs"
by Fengyu Liu
Friday, March 10, 2023 -- 12:00 p.m.
Large Conference Room, 1207 Energy Research Facility
Advisor: Professor Yanne Chembo
Kerr optical frequency combs are a series of discrete, equally spaced spectral lines and are usually generated by pumping a high-Q whispering-gallery mode resonator with a continuous-wave resonant laser. One of the most important applications of Kerr optical frequency combs is ultrapure microwave generation. In this case, the comb is sent to a fast photodetector, and the intermodal radiofrequency of the comb is retrieved. The output signal is a microwave with frequencies corresponding to the intermodal spectral spacing of the comb, and its harmonics. In this talk we present a model where random noise is added to the coupled-mode equations governing the comb dynamics, which allows us to characterize the noise-induced broadening of the spectral lines. We show that the phase noise spectra of the microwaves have two dominant contributions that can be determined theoretically and numerically.