@article{2015-paraiso-painter-phy-rev-x-v5-4-p041024, Abstract = {

We present the design, fabrication, and characterization of a planar silicon photonic crystal cavity in which large position-squared optomechanical coupling is realized. The device consists of a double-slotted photonic crystal structure in which motion of a central beam mode couples to two high- $Q$ optical modes localized around each slot. Electrostatic tuning of the structure is used to controllably hybridize the optical modes into supermodes that couple in a quadratic fashion to the motion of the beam. From independent measurements of the anticrossing of the optical modes and of the dynamic optical spring effect, a position-squared vacuum coupling rate as large as ${˜ g}^{'}$ $/ 2 π = 245 Hz$ is inferred between the optical supermodes and the fundamental in-plane mechanical resonance of the structure at $ω_{m} / 2 π = 8.7 MHz$ , which in displacement units corresponds to a coupling coefficient of $g^{'} / 2 π = 1 THz / {nm}^{2}$ . For larger supermode splittings, selective excitation of the individual optical supermodes is used to demonstrate optical trapping of the mechanical resonator with measured ${˜ g}^{'} / 2 π = 46 Hz$ .

}, Author = {Paraïso, T. K. AND Kalaee, M. AND Zang, L. AND Pfeifer, H. AND Marquardt, F. AND Painter, O.}, Journal = {Physical Review X}, Pages = {041024}, Title = {{Position-squared coupling in a tunable photonic crystal optomechanical cavity}}, Volume = {5 (4)}, Year = {2015} }