Showing posts with label Jaemok Koo. Show all posts
Showing posts with label Jaemok Koo. Show all posts

Saturday, June 23, 2018

Abstract-Electrically Controllable Molecularization of Terahertz Meta‐Atoms


Hyunseung Jung,   Jaemok Koo,   Eunah Heo,   Boeun Cho,   Chihun In,   Wonwoo Lee,   Hyunwoo Jo,  Jeong Ho Cho,   Hyunyong Choi,   Moon Sung Kang,  Hojin Lee,

https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201802760

Active control of metamaterial properties is critical for advanced terahertz (THz) applications. However, the tunability of THz properties, such as the resonance frequency and phase of the wave, remains challenging. Here, a new device design is provided for extensively tuning the resonance properties of THz metamaterials. Unlike previous approaches, the design is intended to control the electrical interconnections between the metallic unit structures of metamaterials. This strategy is referred to as the molecularization of the meta‐atoms and is accomplished by placing graphene bridges between the metallic unit structures whose conductivity is modulated by an electrolyte gating. Because of the scalable nature of the molecularization, the resonance frequency of the terahertz metamaterials can be tuned as a function of the number of meta‐atoms constituting a unit metamolecule. At the same time, the voltage‐controlled molecularization allows delicate control over the phase shift of the transmitted THz, without changing the high transmission of the materials significantly.

Thursday, May 24, 2018

Abstract-Electrically Controllable Reconfiguration of Terahertz Meta-Atoms into Meta-Molecules



Hyunseung Jung, Jaemok Koo, Wonwoo Lee, Moon Sung Kang, and Hojin Lee

https://www.osapublishing.org/abstract.cfm?uri=CLEO_QELS-2018-FM3J.8

We report structural methodology for electrically switchable terahertz metamaterials between atom- and molecule-states by using limited conductance variation of graphene bridges. Based on experimental verification, we confirmed 39% of wide resonance tuning of terahertz metamaterials.
© 2018 The Author(s)