Historically, photonic devices, such as the modulators that encode data onto light beams, have been made of exotic materials. In 2004, however, Intel researcher Mario ­Paniccia and his team showed that with clever engineering, modulators and lasers could be made from silicon. ­Paniccia’s latest invention is shown above. A modulator sits on the millimeter-wide strip of silicon at the center of the device. It has reached speeds of 30 gigabits (the equiva­lent of about 8,000 digital photos) per second, approaching the 40-gigabit-per-second speed of today’s best modulators. Paniccia says his technology could be commercialized by 2010. He adds that 25 silicon lasers combined with “an array of 25 modulators operating at 40 gigabits per second” would yield “a terabit of information all on a piece of silicon the size of my fingernail.”