High‐Q Metallic Fano Metamaterial for Highly Efficient Cerenkov Lasing. Issue 12 (3rd April 2018)

• Record Type: Journal Article
• Authors: Kim, Seontae; Baek, In‐Keun; Bhattacharya, Ranajoy; Hong, Dongpyo; Sattorov, Matlabjon; Bera, Anirban; So, Jin‐Kyu; Kim, Dai‐Sik; Park, Gun‐Sik
• Is Part Of: Advanced optical materials. Volume 6:Issue 12(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-04-03
• Subjects: Cerenkov radiation -- Fano resonances -- high quality factor -- metamaterials -- structural asymmetry; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201800041
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: A high‐quality‐factor (high‐Q) metallic Fano metamaterial is demonstrated both experimentally and theoretically. This material is suitable for highly efficient Cerenkov lasing in which subwavelength metallic slits are arranged to form asymmetric unit cells. In contrast to conventional dielectric Cerenkov or Smith–Purcell devices, in the proposed device, convection electrons traverse the high‐Q metallic metamaterial. The interplay between an extremely low group velocity from the infinite transverse permittivity of the anisotropic metamaterial and the subradiant damping from a Fano‐type slit mode is shown to be responsible for the high‐Q value, which is measured to be unprecedented at 700. The resulting improvement in the Cerenkov lasing efficiency is estimated to be more than two orders of magnitude using a particle‐in‐cell simulation. Abstract : Fano‐type slit modes play a key role in high‐quality‐factor metallic metamaterials, where the subwavelength slits are used to form asymmetric unit cells. Kim et al. focus on maximally trapping the Cerenkov radiation wave to extend its interaction with the electron beam and on controlling the radiation damping, as has been described in Rayleigh scattering to maximize the efficiency of Cerenkov lasing.