Lasers, the highly concentrated light beams once considered unsuitable for long-distance communications, may become the best way to transmit large amounts of data across deep space.
Scientists at the U.S. National Institute of Standards and Technology and NASA’s Jet Propulsion Laboratory say they have developed a tiny array of superconducting light sensors sensitive enough to detect the smallest particle of light - a single photon. Even more, the chip can detect the position - left or right, up or down - of each photon that hits the array.
Light signals can be coded by the position of each photon, and also by the time intervals as they are transmitted. Researchers say this makes possible the transfer of very large volumes of information, more quickly and at lower cost than by using radio - the current standard for data communications in space.
Researchers say the sensors can absorb data from tens of millions of photons per second, and they expect future versions will be capable ot decoding one billion photons per second.
In a recent real-world test of the technique, scientists used arrays of laser sensors to exchange data with a NASA spacecraft orbiting the moon at a rate six times faster than the best radio communications available. Researchers say the laser-based system weighs half as much as comparable radio devices and uses 25 percent less power.