Abstract-Linear frequency conversion via sudden merging of resonances in time-variant terahertz metasurfaces

Kanghee Lee,   Jaehyeon Son,   Byungsoo Kang,   Jagang Park,  Fabian Rotermund,  Bumki Min

http://ieeexplore.ieee.org/document/8067111/


We experimentally demonstrate linear frequency conversion on time-variant terahertz (THz) metasurface. The proposed metasurface is originally designed to have two resonances, and with optical pumping, the resonances are merged into one. When a THz pulse passes through the metasurface during this merging process, a frequency component corresponding to the merged mode is generated.

Abstract-Two-Terminal Graphene Oxide Devices for Electrical Modulation of Broadband Terahertz Waves

1. 1. 
      
2. Seungwoo Lee^1,*, 
3. Kyung Eun Lee², 
4. Won Jun Lee², 
5. Byung Cheol Park³, 
6. Byungsoo Kang³, 
7. Euyheon Hwang^4,* and
8. Sang Ouk Kim^2,*

Article first published online: 16 DEC 2015

DOI: 10.1002/adom.201500577

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

http://onlinelibrary.wiley.com/doi/10.1002/adom.201500577/abstract;jsessionid=7B118B09A2FC6E009805CF6701D21B98.f01t03?userIsAuthenticated=false&deniedAccessCustomisedMessage=

Graphene oxide (GO) can provide a generic way to effectively control broadband THz transmission amplitude, when incorporated into two-terminal electrode devices. Electrically trapped charge carriers within localized impurity states (LIS) of GO, which originate from fully randomized defective structure of GO, result in a large modulation of transmission amplitude (≈30%) for broadband THz waves (≈0.3–2.0 THz) even at room temperature.