title: Experimental Realization of Two Decoupled Directional Couplers in a Subwavelength Packing by Adiabatic Elimination.
abstract: On-chip optical data processing and photonic quantum integrated circuits require the integration of densely packed directional couplers at the nanoscale. However, the inherent evanescent coupling at this length scale severely limits the compactness of such on-chip photonic circuits. Here, inspired by the adiabatic elimination in a N-level atomic system, we report an experimental realization of a pair of directional couplers that are effectively isolated from each other despite their subwavelength packing. This approach opens the way to ultradense arrays of waveguide couplers for integrated optical and quantum logic gates.
authors.forename: Michael
authors.initials: M
authors.lastname: Mrejen
authors.forename: Haim
authors.initials: H
authors.lastname: Suchowski
authors.forename: Taiki
authors.initials: T
authors.lastname: Hatakeyama
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, California 94720, United States.|Department of Physics, King Abdulaziz University , Jeddah, 21589, Saudi Arabia.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang
keywords: Integrated optics devices; atomic molecular and optical physics; nanophotonics; near-field optical microscopy; quantum computing; waveguides