title: Broadband giant-refractive-index material based on mesoscopic space-filling curves.
abstract: The refractive index is the fundamental property of all optical materials and dictates Snell's law, propagation speed, wavelength, diffraction, energy density, absorption and emission of light in materials. Experimentally realized broadband refractive indices remain <40, even with intricately designed artificial media. Herein, we demonstrate a measured index >1,800 resulting from a mesoscopic crystal with a dielectric constant greater than three million. This gigantic enhancement effect originates from the space-filling curve concept from mathematics. The principle is inherently very broad band, the enhancement being nearly constant from zero up to the frequency of interest. This broadband giant-refractive-index medium promises not only enhanced resolution in imaging and raised fundamental absorption limits in solar energy devices, but also compact, power-efficient components for optical communication and increased performance in many other applications.
authors: Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors: Taeyong
authors: T
authors: Chang
authors: Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors: Jong Uk
authors: JU
authors: Kim
authors: Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors: Seung Kyu
authors: SK
authors: Kang
authors: Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors: Hyowook
authors: H
authors: Kim
authors: Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors: Do Kyung
authors: DK
authors: Kim
authors: Department of Physics, KAIST, Daejeon 34141, Republic of Korea.
authors: Yong-Hee
authors: YH
authors: Lee
authors: Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea.
authors: Jonghwa
authors: J
authors: Shin