Low-Phase Noise Microwave Generation using Self-Stabilized $f_{\text{ceo}}$-Free Comb

Due to the inherently low crosstalk between carrier-envelope and repetition rate control mechanisms, difference-frequency generated (DFG) optical frequency combs are an attractive light source for low-phase-noise microwave generation based on feedback control. However, the DFG process adds phase noise to individual comb lines in accordance with the carrier-envelope noise. Here, we stabilized a DFG comb with a 7.5 m interferometer and generated a 10 GHz signal with a phase noise of −123 dBc/Hz at 1 kHz offset frequency.