Seminar : OPTO-MECHANICS BY TRANSFORMATION OPTICS
Davide Mencarelli, Ph.D.
UPVM (Universita Polytechnica delle Marche) in Ancona (Italy)
Friday 25 mai 2018 – 11pm
IEMN – LCI Salle du conseil – Villeneuve d’Ascq
Rigorous approaches to the Electromagnetic/Mechanical problem are needed as a further step towards the development of microwave circuits based on phonon propagation at micro-and nano-scale. In the future, this kind of circuits is likely to integrate opto-mechanically pumped phonon sources and detectors, as well as phonon processing components (waveguides, splitters, memories) to process information by means of phonons.
This presentation proposes a numerical solution of the electromagnetic/mechanical system of equations governing light behavior in opto-mechanical cavities, with the help of an extended version of the Transformation Optics (TO) method. According to its original concept, TO is an analytical tool that facilitates the design of a variety of optical devices (lenses, phase shifters, deflectors, etc.) by deforming the coordinate system, warping space to control the trajectories of the electromagnetic radiation. Such alteration turns into a change of the electromagnetic material parameters such as permittivity and the permeability. For the special case of optomechanics, TO is used to take into account for the time varying boundaries of the computational domain. This kind of calculation allows the development of an efficient generation of microwave coherent phonon sources, by engineering their propagation or coupling with phonon waveguides. The efficiency and the versatility of the strategy is tested by analysing the resonant behaviour of a corrugated Si-based nanobeam and comparing numerical results to experimental ones from the available literature.