‘Twisted’ waves could boost capacity of wi-fi and TV
A striking demonstration of a means to boost the information-carrying capacity of radio waves has taken place across the lagoon in Venice, Italy. The technique exploits what is called the “orbital angular momentum” of the waves – imparting them with a “twist”. Varying this twist permits many data streams to fit in the frequency spread currently used for just one.
The approach, described in the New Journal of Physics, could be applied to radio, wi-fi, and television. The parts of the electromagnetic spectrum that are used for all three are split up in roughly the same way, with a spread of frequencies allotted to each channel. Each one contains a certain, limited amount of information-carrying capacity: its bandwidth.
As telecommunications have proliferated through the years, the spectrum has become incredibly crowded, with little room left for new means of signal transmission, or for existing means to expand their bandwidths.
But Bo Thide of Swedish Institute of Space Physics and a team of colleagues in Italy hope to change that by exploiting an entirely new physical mechanism to fit more capacity onto the same bandwidth.
The key lies in the distinction between the orbital and spin angular momentum of electromagnetic waves.
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Category: World News |