Manipulating Motion with Light: Cavity Optomechanics in Nanophotonic Structures

Qiang Lin
Department of Applied Physics, California Insitute of Technology

Optical control of mechanical motion underlies a variety of applications ranging from laser cooling to optical tweezing, playing a critical role across many multidisciplinary fields extending from atomic physics to molecular biology. In this talk, I will discuss our recent progress in enhancing the relatively weak force exerted by photons through specially designed coupled-disk nano-optomechanical structures. The dramatically enhanced optical force introduces strong nonlinear coupling between the mechanical and optical degrees of freedom of nanophotonic cavities, enabling precise engineering of the optomechanical properties and sensitive probing of the mechanical motion through the optical wave dynamics. This provides a new testbed to study fundamental physics such as quantum optomechanical dynamics at the mesoscopic scale, and also allows to realize novel optical functionalities unprecedented by conventional approaches. I will give a brief overview of the current state of optomechanical research, then will move on to discuss our work on how to use this type of force to excite regenerative mechanical oscillation, cool the mechanical thermal Brownian motion, optically modify the mechanical rigidity, and to induce EIT-like coherent mixing of optomechanical excitations, as well as how to utilize these cavity-optomechanical effects for on-chip photonic signal processing such as broadband wavelength routing, fast optical switching, and other applications.