American and Israeli researchers have used twisted vortex beams to transmit data at 2.5 terabits per second. As far as we can discern, this is the fastest wireless network ever created — by some margin. This technique is likely to be used in the next few years to vastly increase the throughput of both wireless and fiber-optic networks.
These twisted signals use orbital angular momentum (OAM) to cram much more data into a single stream. In current state-of-the-art transmission protocols (WiFi, LTE, COFDM), we only modulate the spin angular momentum (SAM) of radio waves, not the OAM.
SAM differs from OAM in the same way that the Earth's spin differs from its orbit around our Sun -- imagine SAM as a spinning planet and think of OAM as the orbit of that spinning planet as it travels around a star.
Just as the rotational speed of SAM can be used to represent different numbers (i.e. data represented by the number of spins per second), the tightness of spirals produced by OAM can also represent numbers (faster the twist, tighter the spiral). Ultimately, researchers have managed to simultaneously utilize both SAM and OAM to represent data with light, giving them tremendous potential to represent huge ranges of information and deliver it at light speed.
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