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Laser pointer communication system hits 1Gbps, less error-prone than Wi-Fi

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Researchers in Taiwan have created a visible light communication system using everyday laser pointers that achieves 500Mbps speeds with a single link, and 1Gbps using a multiplexed signal from two pointers.

green lasers shutterstock 1000
green lasers shutterstock 1000

Researchers in Taiwan are working on a visible light communication system (VLC) made out of everyday laser pointers. The system achieves 500Mbps speeds with a single link, and 1Gbps using a multiplexed signal from two pointers. Unlike other approaches which use ordinary LED light to transmit data, the coherence of laser light makes it possible to achieve very low error rates when it's used with a preamplifier and filter— about one bit in a billion at distances as far as 10 meters (about 33 feet). Without the pre-amp and filter error rates are about the same as traditional Wi-Fi — one bit in 100,000. Bluetooth, which also has a 10-meter range, has a bit error rate of one in a thousand.

VLC transmits bits using the part of the spectrum we can see, which doesn't pass through most physical barriers or interfere with other communications systems. That makes it an attractive idea where radio-based wireless transmissions would be dangerous or prohibited for security reasons (think hospitals, airplanes and government offices). Of course, one of the advantages of going with LED is that it that it’s dual-purpose; the bulb you’re using to light a room could also be used to provide a data connection (the blinking pulses are too fast to be seen). While the directionality of lasers has the advantage of making secure communications easier (you would be able to see anything that snuck between you and the transmitter), it does have the disadvantage of not being able to light a room, meaning you would need the laser pointer setup (this group built theirs for about $600) in addition to ordinary lighting if you don't want to work in the dark.