Metamaterials are man-made materials that have properties not found in natural materials, such as unusual electromagnetic properties. A typical metamaterial is a periodic assembly of small components, or “meta-atoms.” Invisibility cloaks and "perfect lenses" are designed with metamaterials.
An international collaboration of researchers has recently made a breakthrough in remotely controlling meta-atoms by illuminating them with a pattern of visible light. The team set up metamaterials whose elements contained tunable electronic components. Each meta-atom is connected to a light-sensitive photodiode and can be controlled with a nearby light emitting diode (LED).
When the photodiodes are illuminated, the generated voltage is used to change the resonance of the metamaterial structure. By increasing the brightness of some LEDs and not others, the angle of reflection can be altered non-uniformly and controlled individually.
Image Credit: Ilya Shadrivov/Australian National University
Figure 1. Compilation of multiple metamaterial "stripes" with different illumination patterns.
Image Credit: Ilya Shadrivov/Australian National University
Figure 2. Close up of a single metamaterial "stripe."
1 Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200, Australia
2 National Research University of Information Technologies, Mechanics and Optics (ITMO), St. Petersburg 197101, Russia
3 Instituto de Telecomunicações, Universidade de Coimbra, Pólo II, 3030 Coimbra, Portugal
Synopsis: Tunable Metamaterials (Physics)
"Metamaterials Controlled with Light," Phys. Rev. Lett. 109, 083902 (2012)