Synopsis: Sharp turn ahead for light beams

A two-dimensional array of silicon rods is theoretically shown to bend light around tight corners.
Synopsis figure
Credit: J. Du et al., Phys. Rev. Lett. (2011)

Over the last decade, the field of optics has been turned on its head by artificial materials that bend light in ways that no natural material can. In a new development, theorists have shown that a carefully designed array of tiny rods can deflect a light beam at a sharp angle. As explained in Physical Review Letters, this unique light response is due to interference in the resonant emission from the rods. Arrays like this might help steer light inside fiber optic networks or an optical computer.

Optical wonders like cloaking devices and superlenses rely on negative refractive index materials to radically alter the path of light. These metamaterials typically contain arrays of small metallic components, but researchers are also starting to look at dielectric components. In this vein, Junjie Du of the Chinese Academy of Sciences in Shanghai and his colleagues theoretically investigated how light scatters off half-micron-wide silicon rods when they are lined up like the bars on a cage.

Because of silicon’s strong dielectric properties, each rod resonates like an electric dipole when excited by infrared light. If the rod spacing is chosen just right, the emissions from the different dipoles interfere with one another, resulting in a single beam coming out on the same side of the normal as the incoming beam. The researchers call this negative transmission because, unlike negative refraction, the outgoing beam is in the same medium as the incoming one. The rods may find uses in photonic circuits where their compact size and nearly lossless transmission would be a plus. – Michael Schirber


Announcements

More Announcements »

Subject Areas

Optics

Previous Synopsis

Atomic and Molecular Physics

Linked in

Read More »

Next Synopsis

Related Articles

Viewpoint: Cavity with Iron Nuclei Slows Down X Rays
Optics

Viewpoint: Cavity with Iron Nuclei Slows Down X Rays

Slow light effects have been measured for x rays using a cavity filled with iron nuclei, where the speed of light was reduced by a factor of 10,000. Read More »

Synopsis: Nanofiber Optical Memory
Quantum Information

Synopsis: Nanofiber Optical Memory

Light signals propagating down an ultrathin fiber can be temporarily stored in a cloud of cold atoms surrounding the fiber. Read More »

Synopsis: Zooming in on Failures
Optics

Synopsis: Zooming in on Failures

A near-infrared microscopy technique can detect defects in electronic devices with a resolution better than the diffraction limit of light. Read More »

More Articles