Exploiting cavity optomechanics for phonon lasing (Vol. 48 No. 1)

Mechanical and optical localized modes in an optomechanical photonic crystal cavity

Phonon lasing in a mechanical resonator is a regime in which its oscillations are self-sustained, monochromatic, coherent and of high-amplitude. The main limitations of conventional sources of coherent mechanical waves are that they are not self-sustained nor operate efficiently above a few tens of gigahertz. Phonon lasers overcome the former by definition, while the latter is one of the challenges being tackled to make a real technological impact. Phonon lasers based on optomechanical devices may provide a way out, where advances of nanofabrication techniques help push-up the frequency of the vibration modes that can be tailored and driven by radiation pressure forces, while integration into a high-quality optical cavity allows a dramatic increase of power efficiencies.

This work reviews several mechanisms and techniques that can drive a mechanical mode into the lasing regime by exploiting the radiation pressure force in optomechanical cavities. The authors pay special attention to circular microresonators and optomechanical photonic crystal cavities. The former were the pioneer optomechanical setups demonstrating phonon lasing action while the latter can be chip-integrated enabling straightforward connection to phononic waveguides or membranes for out-coupling the phonon lasing signal.

D. Navarro-Urrios, J. Gomis-Bresco, F. Alzina, N. E. Capuj, P. D. García, M. F. Colombano, E. Chavez-Angel and C. M. Sotomayor-Torres, Self-sustained coherent phonon generation in optomechanical cavities, J. Opt. 18, 094006 (2016)