In what is seen as milestone in telecommunication, US researchers at the University of California in Berkeley have slowed light down in an effort to speed up network communication.
They have shown, for the first time, that the group velocity of light - the speed at which a laser pulse travels along a light wave - can be slowed to about six miles per second in semiconductors, according to their report published in the journal Optics Letters.
While that speed is not exactly the pace of a turtle, it is 31,000 times slower than the 186,000 miles per second that light normally clocks while traveling through vacuum.
"This achievement marks a major milestone on the road to ever faster optical networks and higher performance communications," a university press release said quoting Connie J Chang-Hasnain, professor of electrical engineering and computer science and principal investigator of the project.
The researchers envision a future of 3-D graphics transmission, high-resolution video conferencing as good as face-to-face encounters and quantum memory chips that could boost the power of supercomputers, including those used for complex climate modelling.
Experiments in the past five years have demonstrated that light beams can be slowed or accelerated through atomic vapour as well as solid state crystals. Physicists at Harvard University have even managed to stop light particles in their tracks for 10-20 microseconds in rubidium gas.
The Berkeley-led team is the first to experimentally demonstrate slowing of light using thin layers of semiconductors.
"Semiconductors have one million to one billion times broader bandwidth capacity than atomic gas or crystal," the report said. "This brings real-world practicality to telecommunication and network applications. Another advantage to using semiconductors is the possibility of cost-effective integration into circuitry, specifically photonic integrated circuits."
