Metal-Organic Hybrid Metamaterials for Spectral-Band Selective Active Terahertz Modulators

• Published in: Applied sciences Vol. 11; no. 6; p. 2765
• Main Authors: Yoo, Hyung Keun, Cho, Soo Bin, Park, Sae June, Ahn, Yeong Hwan, Kang, Chul, Hwang, In-Wook, Lee, Joong Wook
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-03-2021
• Subjects: active optics; Butyric acid; Carrier density; Composite materials; Efficiency; Electric fields; Fullerenes; Lasers; Metamaterials; modulators; Radiation; Silicon; Silicon substrates; Simulation; Spectra; Spectral bands; Spectrum analysis; Terahertz frequencies; terahertz spectroscopy; Thin films
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app11062765

Optically controlled spectral-band selective terahertz (THz) modulators based on metal-organic hybrid metamaterials were investigated. An artificially structured material, which consists of two single split-ring resonators put together on the split gap side, was patterned on a silicon substrate to generate frequency-selective properties. An active layer of an organic thin film (fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester, also called PCBM) was deposited on the metamaterial-silicon structure for modulating the transmission of incident THz radiation. The metal-organic hybrid metamaterials enabled active control of spectral bands present in the transmission spectra of THz waves. In addition, the changes in the photo-excited carrier density due to the transfer of charges between the layers were quantitatively analyzed by simulation results.