A Frequency Comb with High Resolution and Low Threshold Power Based on a Single Mode Circular Resonator

This paper reports an intra-mode-coupling phononic frequency comb (PFC) based on a single-mode circular electrostatic resonator. Compared with the performance of related frequency combs, a PFC with high spacing resolution and low pump power threshold is realized. The spacing resolution reaches 0.1 Hz, and the threshold intensity reaches 3 mVpp, which offer new advances to phonon regulation and quantum-based frequency/time transfer. Additionally, the evolution process of PFC is completely observed experimentally.