Parametric Optomechanical Oscillations in Two-Dimensional Slot-Type   High-Q Photonic Crystal Cavities
  We experimentally demonstrate an optomechanical cavity based on an air-slot photonic crystal cavity with optical quality factor Qo=4.2\times10^4 and a small modal volume of 0.05 cubic wavelengths. The optical mode is coupled with the in-plane mechanical modes with frequencies up to hundreds of MHz. The fundamental mechanical mode shows a frequency of 65 MHz and a mechanical quality factor of 376. The optical spring effect, optical damping and amplification are observed with a large experimental optomechanical coupling rate gom/2pi of 154 GHz/nm, corresponding to a vacuum optomechanical coupling rate g*/2pi of 707 kHz. With sub-mW or less input power levels, the cavity exhibits strong parametric oscillations. The phase noise of the photonic crystal optomechanical oscillator is also measured. 
Jiangjun Zheng, Ying Li, Mehmet Sirin Aras, Aaron Stein, Ken L.   Shepard, and Chee Wei Wong
physics.optics