Twisted pasta-shaped waves - a sign of the future?

Italian and Swedish researchers have successfully twisted radio waves to allow a potentially infinite number of channels to be broadcasted and received. The phase twist looks like a fusilli pasta-shaped beam.

The researchers, from the University of Padova in Italy and the Angstrom Laboratory in Sweden, transmitted two manipulated radio waves in the 2.4 GHz band from a lighthouse on San Diego Island to a satellite disk placed on a balcony of Palazzo Ducale in Venice 442 m away. The waves were able to pick up two separate channels.

A wave can twist from its axis a certain number of times either clockwise or anticlockwise; therefore it can adopt several configurations. For example, one can use five orbital angular momentum states, from -5 up to 5, including untwisted waves, and have 11 channels in one frequency band.

This twisted wave may solve the problem of radio congestion and the reduced availability of frequency bands.

The results of the experiment have been reported in the Institute of Physics and German Physical Society's New Journal of Physics.