Position-squared coupling in a tunable photonic crystal optomechanical cavity

Autor: Paraiso, Taofiq K., Kalaee, Mahmoud, Zang, Leyun, Pfeifer, Hannes, Marquardt, Florian, Painter, Oskar
Rok vydání: 2015
Předmět:
Zdroj: Phys. Rev. X 5, 041024 (2015)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevX.5.041024
Popis: 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 which couple in a quadratic fashion to the motion of the beam. From independent measurements of the anti-crossing of the optical modes and of the optical spring effect, the position-squared vacuum coupling rate is measured to be as large as 245 Hz to the fundamental in-plane mechanical resonance of the structure at 8.7MHz, which in displacement units corresponds to a coupling coefficient of 1 THz/nm$^2$. This level of position-squared coupling is approximately five orders of magnitude larger than in conventional Fabry-Perot cavity systems.
Comment: 11 pages, 6 figures
Databáze: arXiv