Feedback enhanced phonon lasing of a microwave frequency resonator

The amplitude of self-oscillating mechanical resonators in cavity optomechanical systems is typically limited by nonlinearities arising from the cavity’s finite optical bandwidth. We propose and demonstrate a feedback technique for increasing this limit. By modulating the cavity input field with a signal derived from its output intensity, we increase the amplitude of a self-oscillating GHz frequency mechanical resonator by 22% (an increase in coherent phonon number of 50%), limited only by the achievable optomechanical cooperativity of the system. This technique will advance applications dependent on high dynamic mechanical stress, such as coherent spin-phonon coupling, as well as the implementation of sensors based on self-oscillating resonators.

We wish to acknowledge the support from Alberta Innovates (Strategic Research Project), the Government of Alberta Major Innovation Fund, the Canadian Foundation for Innovation, the National Research Council (NanoInitiative Program), and the Natural Sciences and Engineering Research Council of Canada (Discovery Grant and Strategic Partnership Grant programs).

Peyman Parsa: Conceptualization (supporting); Data curation (lead); Formal analysis (lead); Investigation (lead); Methodology (lead); Software (lead); Validation (equal); Visualization (equal); Writing – original draft (lead); Writing – review & editing (supporting). Prasoon Kumar Shandilya: Conceptualization (supporting); Investigation (supporting); Project administration (equal); Software (supporting); Validation (equal); Visualization (supporting). David P. Lake: Conceptualization (lead); Resources (equal). Matthew E. Mitchell: Conceptualization (supporting); Resources (equal). Paul E. Barclay: Funding acquisition (lead); Project administration (equal); Resources (equal); Supervision (equal); Validation (equal); Visualization (equal); Writing – original draft (supporting); Writing – review & editing (lead).

The data that support the findings of this study are available from the corresponding author upon reasonable request.

The authors have no conflicts to disclose.