Tiny Antennas Help Create Innovative Hologram Technology
19 November 2013
US scientists have developed a new hologram technology that could find application in advanced sensors, high-resolution displays and information processing, providing the means for the integration of extremely small "planar photonics" devices and optical switches into computer chips.
The researchers at Purdue University were successful in the creation of tiny holograms using a "metasurface" comprised of thousands of V-shaped nanoantennas, which can perform ultra-efficient control of light. The nanoantennas are formed into a super thin gold foil, said Alexander Kildishev, associate research professor of electrical and computer engineering at Purdue.
The technology uses laser that sends out rays of light through the nanoantennas to create a hologram which is 10 microns above the metasurface. As a demonstration, the scientists created a hologram of the word PURDUE, which was less than 100 microns wide, or about the width of a human hair. They also showed how the intensity and timing of laser light can be controlled as it passes through the nanoantennas, thanks to the "phase delay" that each antenna has.
Metasurfaces could prove an excellent platform for using single photons for switching and routing in advanced computer technology, providing for substantial speed acceleration in computers and telecommunications. The size of conventional photonic devices cannot be dramatically reduced due to the wavelength of light, which is too large to suit small parts needed for integrated circuits. But with nanostructured materials this can be achieved, paving the way for the creation of new types of nanophotonic devices, according to Vladimir M. Shalaev, scientific director of nanophotonics at Purdue's Birck Nanotechnology Center.