Coupling of atomic quadrupole transitions with resonant surface plasmons

• Main Authors: Chan, Eng Aik, Adamo, Giorgio, Zheludev, Nikolay I., Ducloy, Martial, Wilkowski, David, Syed Abdullah Aljunid
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2019
• Subjects: Science::Physics; Optics & Lasers; Metamaterials
• Online Access: https://hdl.handle.net/10356/87833; http://hdl.handle.net/10220/49306
• Institution: Nanyang Technological University

We report on the coupling of an electric quadrupole transition in atomic vapor with plasmonic excitation in a nanostructured metallic metamaterial. The quadrupole transition at 685 nm in the gas of cesium atoms is optically pumped, while the induced ground-state population depletion is probed with light tuned on the strong electric dipole transition at 852 nm. We use selective reflection to resolve the Doppler-free hyperfine structure of cesium atoms. We observe a strong modification of the reflection spectra at the presence of metamaterial and discuss the role of the spatial variation of the surface plasmon polariton on the quadrupole coupling.