Optomechanics in an ultrahigh-Q two-dimensional photonic crystal cavity

We demonstrate an ultrahigh-Q slotted two-dimensional photonic crystal cavity capable of obtaining strong interaction between the internal light field and the mechanical motion of the slotted structure. The measured optical quality factor is Q=1.2x10(6) for a cavity with an effective modal volume of V-eff=0.04(lambda)(3). Optical transduction of the thermal motion of the fundamental in-plane mechanical resonance of the structure (nu(m)=151 MHz) is performed, from which a zero-point motion optomechanical coupling rate of g*/2 pi=320 kHz is inferred. Dynamical back-action of the optical field on the mechanical motion, resulting in cooling and amplication of the mechanical motion, is also demonstrated. (C) 2010 American Institute of Physics. [doi:10.1063/1.3507288]