Logo: University of Southern California

February 5th, 2010

Harnessing optical forces on a silicon chip
nanomechanics meets nanophotonics 

Mo Li
Department of Electrical Engineering, Yale University

Seminar: SSL 150 at 2.00pm on Friday 5th, February, 2010

The force exerted by photons is of fundamental importance in light-matter interactions. For example, optical tweezers have been widely used to manipulate atoms and microscale dielectric particles. This optical force was theoretically expected to be greatly enhanced in nanophotonic devices in which light intensity is highly concentrated. Recently, we reported the direct detection and exploitation of transverse gradient optical force in an integrated silicon photonic circuit. We showed that an NEMS resonator embedded in a silicon waveguide can be actuated efficiently by the optical force. We further experimentally proved theoretical predictions that this optical force is bipolar – its direction can be tuned to attractive or repulsive by changing the relative optical phase of coupled lightwaves. Subsequently, we have exploited optical forces in a variety of optomechanical structures, including photonic crystal and micro-disk optical resonators. Harnessing the optical force on a silicon chip will enable new nanophotonic and nanomechanical device functions, such as all-optical switching, tunable nanophotonic, radio-frequency photonics and large-scale integration of NEMS.

Mo Li currently is a postdoctoral associate in Department of Electrical Engineering at Yale University. He received Ph.D. (2007) in Applied Physics from Caltech, M.S. (2003) in Physics from UC San Diego, and B.S. (2001) in Physics from Univ. of Science and Technology of China (USTC). His primary research interests are nano-electromechanical systems (NEMS), nanophotonics, nano-optomechanical systems (NOMS) and integrated quantum photonics.