Enhancing the Magnetic Resonance via Strong Coupling in Optical Metamaterials. Issue 20 (21st August 2017)

• Record Type: Journal Article
• Authors: Zhang, Chen; Fang, Jimao; Yang, Wenhong; Song, Qinghai; Xiao, Shumin
• Is Part Of: Advanced optical materials. Volume 5:Issue 20(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-08-21
• Subjects: avoided resonance crossing -- magnetic resonance -- plasmonic nanostructures -- surface plasmon polaritons; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201700469
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Due to the lack of symmetry between electric and magnetic charges, the magnetic effect in optical materials is usually very weak. Recently, Fano type magnetic resonances have been proposed and experimentally realized by packaging the metallic nanoparticles into metamolecules. However, the corresponding experiments are hard to be realized and the enhancements of magnetic fields are relatively low. Here, a simple way is demonstrated experimentally to generate magnetic plasmon polaritons (MPPs) in optical metamaterials. By changing the period of the nanostructures, strong coupling between the magnetic resonance and the propagating surface plasmon polaritons (SPPs) with a Rabi‐splitting around 190 meV has also been observed. Interestingly, the hybrid modes around the avoided resonance crossing points are found to be mixtures of MPPs and SPPs. Consequently, the typical long‐lived SPPs are also well localized within the dielectric spacer layer and give an enhancement in magnetic field around 500 times. In addition, the dependence of MPPs has also been observed on the refractive index with a sensitivity around 470 nm RIU −1, which is very close to the typical reports of electric resonances in plasmonic nanostructures. This research shall pave a new way to the developments of magnetic light sources and magnetic sensing. Abstract : Enhancement of magnetic fields is experimentally demonstrated in 1D grating‐based optical metamaterials. Through the strong coupling between propagating surface plasmon polaritons and localized magnetic plasmon polaritons, the magnetic field is enhanced more than 500 times and a sensitive refractive index sensor is realized. This research can pave a new way to the development of magnetic light sources and sensors.