Squeezing data onto a laser

Scientists have developed a single-laser system that can carry optical data at transmission rates of up to 26 terabits per second — the highest ever reported for a single laser. The work, published online this week in Nature Photonics, will not only help to fulfil the ever-increasing demands of high-bandwidth communication but also provide an environmentally friendly way of transmitting information over long distances.Achieving terabit-per-second optical transmission rates usually requires the use of multiple lasers and/or complex modulation formats. Juerg Leuthold and co-workers used a single laser to generate 325 optical frequencies within a narrow spectral band of laser wavelengths from 1,533-1,565.5 nm and transmitted the encoded data over 50 km of standard single-mode fibre at data rates of up to 26 terabits per second. The success of the technique is largely due the use of an optical fast Fourier transformation encoding and decoding scheme, which is capable of processing high-bit-rate data in an energy-efficient, real-time manner.The achievement suggests that high-speed optical signal processing could be the answer for meeting the needs of future energy-efficient communication.