title: Plasmonic waveguide ring resonators with 4 nm air gap and λ0(2)/15,000 mode-area fabricated using photolithography.
abstract: Plasmonic air-gap disk resonators with 3.5 μm diameter and a 4 nm thick, 40 nm wide air gap for a mode area of only λ0(2)/15,000 were fabricated using photolithography only. The resonant modes were clearly identified using tapered fiber coupling method at the resonant wavelengths of 1280-1620 nm. We also demonstrate the advantage of the air-gap structure by using the resonators as label-free biosensors with a sensitivity of 1.6 THz/nm.
authors.affiliation: Department of Physics and ‡Graduate School of Nanoscience and Technology, KAIST 373-1 Guseong-dong, Yuseong-Gu, Daejeon, South Korea.
authors.forename: Jaehak
authors.initials: J
authors.lastname: Lee
authors.forename: Juhee
authors.initials: J
authors.lastname: Song
authors.forename: Gun Yong
authors.initials: GY
authors.lastname: Sung
authors.forename: Jung H
authors.initials: JH
authors.lastname: Shin
keywords: Plasmonics; biosensor; microcavity; nanofabrication