Anti-reflection coating design for metallic terahertz meta-materials [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Basic Energy Sciences, 2018.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- pages 2,917-2,927 : digital, PDF file
- Additional Creators:
- SLAC National Accelerator Laboratory
United States. Department of Energy. Office of Basic Energy Sciences
Belgium. Office of the European Research Council Executive Agency (ERCEA)
National Science Foundation (U.S.)
United States. Department of Energy. Office of Scientific and Technical Information
- We demonstrate a silicon-based, single-layer anti-reflection coating that suppresses the reflectivity of metals at near-infrared frequencies, enabling optical probing of nano-scale structures embedded in highly reflective surroundings. Our design does not affect the interaction of terahertz radiation with metallic structures that can be used to achieve terahertz near-field enhancement. We have verified the functionality of the design by calculating and measuring the reflectivity of both infrared and terahertz radiation from a silicon/gold double layer as a function of the silicon thickness. We have also fabricated the unit cell of a terahertz meta-material, a dipole antenna comprising two 20-nm thick extended gold plates separated by a 2 μm gap, where the terahertz field is locally enhanced. We used the time-domain finite element method to demonstrate that such near-field enhancement is preserved in the presence of the anti-reflection coating. Finally, we performed magneto-optical Kerr effect measurements on a single 3-nm thick, 1-μm wide magnetic wire placed in the gap of such a dipole antenna. The wire only occupies 2% of the area probed by the laser beam, but its magneto-optical response can be clearly detected. Our design paves the way for ultrafast time-resolved studies, using table-top femtosecond near-infrared lasers, of dynamics in nano-structures driven by strong terahertz radiation.
- Published through SciTech Connect.
Optics Express 26 3 ISSN 1094-4087; OPEXFF AM
Matteo Pancaldi; Ryan Freeman; Matthias Hudl; Matthias C. Hoffmann; Sergei Urazhdin; Paolo Vavassori; Stefano Bonetti.
Swedish Research Council
European Union Programme
Spanish Ministry of Economy, Industry and Competitiveness
- Funding Information:
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