'Time telescope' could boost web

BBC News reports that researchers have demonstrated a 'time telescope' that could squeeze much more information into the data packets sent around the internet.

Rather than focusing information-carrying light pulses in space, like a normal lens, it focuses them in time.

The telescope comprises laser beams that combine in a tiny silicon structure to compress the pulses.

A prototype device, described in Nature Photonics, boosted the data rate of telecoms-wavelength pulses by 27 times.

A general rule in physics is that the shorter a pulse is in time, the higher its "bandwidth" - a measure of the spread of colours within it, and therefore of its information-carrying capacity.

State-of-the-art devices used in telecommunications today generate pulses with a bandwidth of 10 GHz, using standard electronics to encode information onto those pulses directly.

Purely optical systems can generate pulses with a bandwidth nearly 100,000 times higher. However, getting the information onto the pulses, or modulating them, has been beyond the reach of the electronics that are currently used.

Light pulses are spread out in space; if an instantaneous snapshot could be taken of them, those that are longer in time would appear physically larger.

The trick to the new work is to use "temporal lenses" that can squash comparatively long pulses in time by selectively speeding up or slowing down their different parts.

Read the full BBC News item 'Time telescope' could boost web at:
http://news.bbc.co.uk/1/hi/technology/8281544.stm