Tunable double optomechanically induced transparency in photonically and phononically coupled optomechanical systems

The absorption properties in double optomechanical cavities coupled by the photonic and phononic paths are investigated. The sideband absorption peaks and the transparency dips, located symmetrically around the resonant point, characterize the respective effects of the photonic and phononic interactions on the transparency spectra: the sideband absorption peaks move outward with increase of the photonic interaction due to the normal-mode splitting, and the distance between the two sideband transparency dips is determined by the phononic interaction strength. Meanwhile, the study reveals the competition and the harmonization between the photonic and phononic interactions. When simultaneously switching on the photonic and phononic paths, it is shown from the absorption spectra that the features of the interacting path with stronger strength dominate over the other one with weaker strength. Additionally, the transparency around the resonant point manifests the destructive interference between the photonic and phononic coupling paths when the strength of two paths are comparable. These findings display the flexible tunability of the transparency, and can be used to distinguish between the two quantum paths in the absorption spectrum. (C) 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement