A new old idea

摘要

When most people switch on a desk lamp, they usually want a little extra illumination. But not John Goodey, an engineering student at Oxford University. When he flicks the switch and turns on his lamp, a sensor on his desk downloads music tracks digitally encoded within tiny flickers in the lamp's light. The music is then relayed through a pair of nearby speakers. This unusual set-up offers a glimpse of a future in which light, rather than radio waves, is used to send information. The concept, known as optical wireless or free-space optics (fso) promises better security and higher data-transfer rates (up to 10 gigabits per second) than existing radio-based communications technologies, says Dominic O'Brien, a leading engineer in the field and Mr Goodey's research supervisor at Oxford.