Optical modulation of coherent phonon emission in optomechanical cavities

Jeremie Maire,Amadeu Griol,Daniel Navarro-Urrios,Alejandro Martinez,Guillermo Arregui,Martin F Colombano,Clivia M Sotomayor-Torres,Nestor E Capuj

doi:10.1063/1.5040061

Abstract

Optomechanical structures are well suited to study photon-phonon interactions, and they also turn out to be potential building blocks for phononic circuits and quantum computing. In phononic circuits, in which information is carried and processed by phonons, optomechanical structures could be used as interfaces to photons and electrons thanks to their excellent coupling efficiency. Among the components required for phononic circuits, such structures could be used to create coherent phonon sources and detectors. Complex functions other than emission or detection remain challenging and addressing a single structure in a full network proves a formidable challenge. Here, we propose and demonstrate a way to modulate the coherent emission from optomechanical crystals by external optical pumping, effectively creating a phonon switch working at ambient conditions of pressure and temperature and the working speed of which (5 MHz) is only limited by the mechanical motion of the optomechanical structure. We additionally demonstrate two other switching schemes: harmonic switching in which the mechanical mode remains active but different harmonics of the optical force are used, and switching to- and from the chaotic regime. Furthermore, the method presented here allows to select any single structure without affecting its surroundings, which is an important step towards freely controllable networks of optomechanical phonon emitters.

Highlights

Numerous technologies have been tapping in the vast potential arising from manipulating excitations, among which electrons and photons are two of the most widespread examples
It is clear that the resonance displays similar regimes, including lasing regimes in which the mechanical mode is excited by different harmonics of the optical force, from the 5th to the 1st, as the driving wavelength increases, but shifted to longer wavelengths when additional pumping is introduced
We have presented in this work a proof of concept of modulation of phonon emission, one of the crucial functions to implement phononic circuitry, as well as examples of modulation between different states of the optomechanical system

Summary

Introduction

Numerous technologies have been tapping in the vast potential arising from manipulating excitations, among which electrons and photons are two of the most widespread examples. To use phonons in a similar way remains challenging since their coherent creation, manipulation, and detection, being key elements for their practical use, prove difficult to realize. Due to the lack of discrete phonon transitions in solids at ambient conditions, major efforts have been deployed to generate coherent phonons. These phonon sources can be used for on-chip metrology and time-keeping[1] or mass/force sensing,[2] amongst other foreseen applications.[3] Optomechanical (OM) crystals have.

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