Metamaterials tagged posts

A 3D terahertz gradient-refractive index lens designed by transformation optics is achieved by fabricating “woodpile” structures with varying dimensions of subwavelength dielectric unit cells using the projection microstereolithography technique. Both simulation and experimental investigations confirm that the lens delivers an imaging resolution very close to the diffraction limit over a frequency range from 0.4 to 0.6 THz.

The new lens could be used for biomedical research and security imaging. “Terahertz is somewhat of a gap between microwaves and infrared,” said NW University’s Cheng Sun. “People are trying to fill in this gap because this spectrum carries a lot of information...

The smallest lattice in the world is visible under the microscope only. Struts and braces are 0.2 µm in diameter. Total size of the lattice is about 10 µm. Credit: J. Bauer / KIT

Scientists have now presented the smallest human-made lattice structure. 3D lattice with glassy carbon struts and braces of <200 nm in diameter has higher specific strength than most solids. They are smaller than comparable metamaterials by a factor of five. Apps may include electrodes, filters or optical components.

“Lightweight construction materials, such as bones and wood, are found everywhere in nature,” said Dr.-Ing. Jens Bauer of Karlsruhe Institute of Technology (KIT)...