| AVS 64th International Symposium & Exhibition | |
| MEMS and NEMS Group | Monday Sessions |
| Session MN+EM+NS-MoA |
| Session: | Nano Optomechanical Systems/Multiscale Nanomanufacturing |
| Presenter: | Eduardo Gil Santos, Universite Paris Diderot, France |
| Authors: | E. Gil Santos, Universite Paris Diderot, France W. Hease, Universite Paris Diderot, France A. Lemaitre, Centre de Nanosciences et Nanotechnologies, France M. Labousse, Universite Paris Diderot, France C. Ciuti, Universite Paris Diderot, France G. Leo, Universite Paris Diderot, France I. Favero, Universite Paris Diderot, France |
| Correspondent: | Click to Email |
Optomechanical resonators have been the subject of extensive research in a variety of fields, such as sensing, communication and quantum technologies. Our recent investigations on the capabilities of optomechanical semiconductor disk resonators to operate as sensors in liquids have revealed an astonishing potential. Minimum mass detection of 14·10-24 g, density changes of 2·10-7 kg/m3 and viscosity changes of 5·10-9 Pa·s, for 1s integration time, are extrapolated from our measurements in liquids.
After landmark experiments realized on single resonators, the use of multiple optomechanical cavities is essential to further improve their sensing capabilities, as it enlarges the sensing area while keeping their individual assets. This evolution towards collective nano-optomechanics hence bears potential for a variety of sensing applications, but for quantum or topological photonics as well. Unfortunately, the collective configurations are usually impeded by the residual disorder imposed by nanofabrication techniques, which naturally detunes high optical Q resonators and precludes resonant interactions between them. Therefore, overcoming fabrication imperfections and allowing spectral alignment of resonators is essential.
Here, we develop a new simple and scalable post-fabrication method to achieve such alignment in a permanent manner. The method introduces an approach of cavity-enhanced photoelectrochemical (PEC) etching in a fluid (gas or liquid). This resonant process is highly selective and allows controlling the resonator size with sub-pm precision, well below the material’s interatomic distance. Light resonantly injected into the optical mode of an optical resonator immersed in a fluid triggers an etching process, leading to a fine-tuning of the resonator’s dimensions. The evolution of dimensions is monitored continuously by tracking the resonator’s optical resonance with a laser. This tuning process is naturally scalable to multiple resonators. We demonstrate it using a cascaded configuration where optomechanical disk resonators, each supporting its own localized optical and mechanical mode, are unidirectionally coupled through a common optical waveguide. The technique is illustrated by finely aligning up to five resonators in liquid and two in air, opening the way of fabricating large networks of identical resonators.
As an example of application of this tuning technique, we explore the resonant optical interaction of multiple nano-optomechanical systems. We observe a first form of collective behavior involving several distant resonators, where a unidirectional flow of light frequency-locks a chain of nano-optomechanical oscillators.