Phononic frequency comb via three-mode parametric three-wave mixing

This paper is motivated by the recent demonstration of three-wave mixing based phononic frequency comb. While the previous experiments have shown the existence of three-wave mixing pathway in a system of two-coupled phonon modes, this work demonstrates a similar pathway in a system of three-coupled phonon modes. The paper also presents a number of interesting experimental facts concomitant to the three-mode three-wave mixing based frequency comb observed in a specific micromechanical device. The experimental validation of three-mode three-wave mixing along with the previous demonstration of two-mode three-wave mixing points to the ultimate possibility of multimode frequency combs.