The first metamaterial electro-optic modulator for the telecommunications band

Current efforts in metamaterials research focus on attaining dynamic functionalities such as tunability, switching and modulation of electromagnetic waves¹. To this end, various approaches have emerged, including embedded varactors², phase-change media^{3, 4}, the use of liquid crystals^{5, 6}, electrical modulation with graphene^{7, 8} and superconductors⁹, and carrier injection or depletion in semiconductor substrates^{10, 11}. However, tuning, switching and modulating metamaterial properties in the visible and near-infrared range remain major technological challenges: indeed, the existing microelectromechanical solutions used for the sub-terahertz¹²and terahertz^{13, 14, 15} regimes cannot be shrunk by two to three orders of magnitude to enter the optical spectral range. Here, we develop a new type of metamaterial operating in the optical part of the spectrum that is three orders of magnitude faster than previously reported electrically reconfigurable metamaterials. The metamaterial is actuated by electrostatic forces arising from the application of only a few volts to its nanoscale building blocks—the plasmonic metamolecules—that are supported by pairs of parallel strings cut from a flexible silicon nitride membrane of nanoscale thickness. These strings, of picogram mass, can be driven synchronously to megahertz frequencies to electromechanically reconfigure the metamolecules and dramatically change the transmission and reflection spectra of the metamaterial. The metamaterial’s colossal electro-optical response (on the order of 10⁻⁵–10⁻⁶ m V⁻¹) allows for either fast continuous tuning of its optical properties (up to 8% optical signal modulation at up to megahertz rates) or high-contrast irreversible switching in a device only 100 nm thick, without the need for external polarizers and analysers.

Ref:

An electromechanically reconfigurable plasmonic metamaterial operating in the near-infrared
J. Y. Ou, E. Plum, J. Zhang, and N. I. Zheludev
Nature Nanotech. 8, 252-255 (2013) doi: 10.1038/NNANO.2013.25

Press coverages

Exotic optics: Metamaterial world
Nature: News Feature, Aug 2013 – link

Electrical signals dictate optical properties
Nanotechnology Now, Mar 2013 – link

Electrical Signals Dictate Optical Properties
Science Daily, Mar 2013 – link

Electrical signals dictate optical properties of metamaterial
Laser Focus World, Mar 2013 – link

Metamaterial with adjustable optical properties
R&D, Mar 2013 – link

Variable-property metamaterial has optical application potential
the ENGINEER, Mar 2013 – link