Nonlinear Physics for the Engineering of Phononic Frequency Combs*

Phononic frequency combs (PFC) represent a new nonlinear phenomenon in the physical domain of micromechanical resonators [1]. The emergence of PFC is mediated by nonlinear modal coupling. Through a series of experiments with micromechanical resonators, various features of PFC have now been identified. These include drive parameters for comb operation, hysteresis for comb spectrum tailoring and evolving spectral envelopes of combs. Potential applications of PFC include high-precision sensing, spread spectrum information processing and other applications in timing and frequency control. However, for the successful realization of such applications, the nonlinear physics of micromechanical resonators underlying the evolution of PFC must be fully elucidated. Specific future directions include developing experimental protocols for engineering frequency combs at low drive power levels; resonant and off-resonant excitation; understanding comb frequency fluctuations; tailoring combs for broadband multi-octave spanning spectra; and modelling sensitivity to system parameters and physical perturbations.

[1] Ganesan, A., Do, C. and Seshia, A., 2017. Phononic frequency comb via intrinsic three-wave mixing. PRL 118(3), p.033903.