Directing Light Signals by Polarization
Despite all of us using electronic devices to access the Internet, its backbone is comprised of optical connections because light can carry more information faster than electricity can. For these reasons researchers are working to integrate photonics into our electronics, but converting an optical signal to an electrical one is not easy. Researchers at Harvard University however have recently created a device with the ability to not only convert optical signals to electrical ones, but also direct different signals in different directions.
Part of the reason optics are so efficient when it comes to transmitting information is that light can be polarized. This means that the light strikes a surface with a particular pattern, such as straight lines, right-handed turns, and left handed turns. The device the researchers created responds differently to these polarizations, causing the signals they carry to be sent in different directions. Previously the only way to direct these signals was to realign the light source for each one, which is impractical for real-world use.
The device itself is a plasmonic coupler made of a thin sheet of gold with special perforations in it. The pattern of perforations is what causes the signals to travel in different directions upon striking the coupler.
Source: Harvard University