title: Subwavelength multilayer dielectrics: ultrasensitive transmission and breakdown of effective-medium theory.
abstract: We show that a purely dielectric structure made of alternating layers of deep subwavelength thicknesses exhibits novel transmission effects which completely contradict conventional effective medium theories exactly in the regime in which those theories are commonly used. We study waves incident at the vicinity of the effective medium's critical angle for total internal reflection and show that the transmission through the multilayer structure depends strongly on nanoscale variations even at layer thicknesses smaller than λ/50. In such deep subwavelength structures, we demonstrate dramatic changes in the transmission for variations in properties such as periodicity, order of the layers, and their parity. In addition to its conceptual importance, such sensitivity has important potential applications in sensing and switching.
authors.affiliation: Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Hanan
authors.initials: H
authors.lastname: Herzig Sheinfux
authors.affiliation: Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Ido
authors.initials: I
authors.lastname: Kaminer
authors.affiliation: Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Yonatan
authors.initials: Y
authors.lastname: Plotnik
authors.affiliation: Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Guy
authors.initials: G
authors.lastname: Bartal
authors.affiliation: Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Mordechai
authors.initials: M
authors.lastname: Segev