Wireless data may have a better future than we thought, as American and Israeli researchers have now used “twisted vortex beams” to transmit data at 2.5 terabits per second!
From our current point of wireless data transmission 2.5terabits per second (tbps) is one of the fastest if not the current fastest wireless data transmissions in the world!
As the current states of data transmission protocols are WiFi, LTE or COFDM, with these types of data transmission we only modulate the (Spin Angular Momentum) (SAM) of these radio waves, this isn’t OAM( Orbital Angular Momentum).
To better describe this, picture planet earth being SAM moving by itself (just its angular rotation) while OAM is our movement around the sun. (Creating an oval shape)
The breakthrough here is that researchers have been able to create a wireless network signal that uses both OAM and Sam.
This looks a lot like the picture below, as the field rotates around an object it also rotates itself, creating a vortex looking pattern.
From this research Alan Willner from the University of Southern California, NASA’s Jet Propulsion Laboratory, Tel- Aviv University and fellow researchers were able to twist together 8 – 300Gbps of visible light data streams using Oak and SAM. Here each of the 8 OAM beams had different OAM directions.
They were able to bunch the beams into 2 groups of 4. Each of these passed through a polarization filter. The produced beam architecture now took the shape of, one central beam lieing in the middle. While the others would obit just outside it.
The beam is then transmitted over a small open space (about 1 meter). Much like a ordinary wireless signal it was “untwisted” – decoded at the receiver which processed the signal kicking out a whopping 2.5tbps.
This achievement comes quite recently after Bo Thide proved that OAM transmission was possible. As Bo Thide and his team where able transmit an OAM signal 442 meters. (1450ft) A picture of this signal is showcased below:
Thide announced that OAM transmission could allow us to wrap together an infinite number of transmission protocols without leaving one spectrum, this could increase the signal of ordinary WiFi or LTE connections by 100% – 1000%. This would drastically change the way we use mobile cloud technologies forever. There are many useful applications of these devices.
Willner’s OAM link has a spectral efficiency of 95.7 bits per hertz:
LTE maxes out at 16.32 bits/Hz; 802.11n is 2.4 bits/Hz.
Digital TV (DVB-T) is just 0.55 bits/Hz.
The next task at hand now is to increase the range of the transmission of OAM signals to more than 1 meter so they can become usable within the modern world today.
Willner tells the BBC:
“In reality, the main limiting factor is that we simply don’t have the hardware or software to manipulate OAM. The future of wireless networking is very bright indeed, however.”