Physicists Twist Light, Send 'Hello World' Message Between Islands

Physicists Twist Light, Send 'Hello World' Message Between Islands

When people communicate with each other over electronic devices billions of bits are being sent from one person to the other, containing the information. A recent study has concluded that by bending light waves and filling them with information, it will act as a more efficient method of communication.

There are four ways to get information in and out of light. Radio is a form of light as well as lasers used in  fiber optics. Using the amplitude of the wave, like in AM radio, the wave's frequency, FM radio, and the phase and polarization used in fiber optics with the combination of the first two. These degrees of freedom, as they're called, unfortunately limit how much information can be sent and opened. 

This is the problem that an international team from the University of Vienna wanted to see if they could encode information into the angular momentum of a light wave and send it far enough to be useful, sending it 88 miles (142 kilometers) between two observatories in the Canary Islands.

Mario Krenn, a doctoral student at the University of Vienna and the lead author of one of the two studies outlining the results, said "When we do an additional degree of freedom, you can use the same channel  [a wavelength of light], and increase the amount of information by a factor of n,". "n" can be described as the number of "modes" in the light's angular momentum. Modes are integer multiples of angular momentum measurements. A transmission with five modes, for example, and 10 channels, would now have the capability of sending five times as much information as the original 10 channels could. 

A good explanation of how the scientists did this experiment is thinking of shining a flashlights over a dark surface. When there is no other light present the flashlight makes a ring of light, or a circle. Basically, the scientists did the same thing, except they just made the ring of light into the words "Hello World", and they also used a laser. 

The main problem scientists before them had was making sure the angular momentum of the wave could go far enough. Previous scientists thought that angular momentum was subject to the humidity and air pressure, making it an unreliable method. Fortunately, it isn't and surprised scientists when the information was received over 3km away. Weirdly, it still isn't clear why is goes so far or how it works, as we know is that it does.