Hyperfine phononic frequency comb

TL;DR

This paper reports the first experimental observation of a phononic frequency comb generated through intrinsic mode coupling, revealing new nonlinear dynamics and control mechanisms in acoustic systems with potential broad applications.

Contribution

It introduces the first experimental evidence of a phononic frequency comb formed via intrinsic mode coupling, expanding the understanding of nonlinear phononic phenomena.

Findings

First experimental evidence of phononic frequency comb

Control of comb features through drive parameters

Interplay between nonlinear resonances and Duffing phenomenon

Abstract

Optical frequency combs [1-8] have resulted in significant advances in optical frequency metrology and found wide application to precise physical measurements [1-4, 9] and molecular fingerprinting [8]. A direct analogue of frequency combs in the phononic or acoustic domain has not been reported to date. In this letter, we report the first clear experimental evidence for a phononic frequency comb. In contrast to the Kerr nonlinearity [10] in optical frequency comb formation, the phononic frequency comb is generated through the intrinsic coupling of a driven phonon mode with an auto-parametrically excited sub-harmonic mode [16]. Through systematic experiments at different drive frequencies and amplitudes, we portray the well-connected process of phononic frequency comb formation and define attributes to control the features [17-18] associated with comb formation in such a system. Further, the interplay between these nonlinear resonances and the well-known Duffing phenomenon [12-14] is also observed. The presented pathway for phononic frequency comb formation finds general relevance to other nonlinear systems in both classical and quantum domains.