Most of the communication systems today operate based on light propagated using optical fibres. Hence it is important to achieve a perfect control over light to make communication efficient. For example, we should be able to isolate light by permitting it to travel only in one direction, may be by limiting the forward and backward movements of light waves into dedicated channels.
The current technique to achieve this is to use so called optical isolators, which are made of synthetic crystals interfaced with permanent magnets. However,neither these exotic crystals nor magnetic fields are readily available.
A team of scientists from Yale University, U.S.A. has developed an alternate method to control light waves by coupling it with sound waves. They demonstrated that modulating light waves by ultrasonic waves (high frequency sound waves)results in controlling the behaviour of light wavesin a silicon chip. This restrictslight waves to move in a single direction over large wavelength ranges, often a hundred times greater ranges than that previously observed.
A significant milestone in photon-based communication!