NZ scientists behind new way to capture light

Researchers at the university's Laser Physics Research Group have demonstrated for the first time what's called the "temporal tweezing of light". Photo / Thinkstock

Can you hold light with tweezers?

Well, in a way, yes, University of Auckland scientists have found.

Researchers at the university's Laser Physics Research Group have demonstrated for the first time what's called the "temporal tweezing of light", in a breakthrough that may play a role in the way data is processed over the internet in the future.

While everyday mechanical tweezers move objects around in space and come in handy whenever we need to manipulate something too tiny for our fingers, like pulling a prickle out, the tweezers used by the Auckland researchers were a little more special.

The temporal light tweezers they drew upon are made of laser light themselves and are able to do something similar - they allow the time separation between separate pulses of light to be changed.

The technique works on pulses of light travelling in a loop of fibre optical cable - the same cable used to bring broadband to homes.

These pulses of light are separated in time, one trailing the other.

Temporal light tweezers are able to speed up or slow down individual light pulses and so change their temporal separation - for example an initial separation of one hundred picosecond, or one hundred millionth of a millionth of a second, can be changed to fifty picosecond.

This is the first time arbitrary modification of the spacing between two light pulses travelling in a fibre loop has been achieved.

The Auckland team was able to independently manipulate several pulses at once.

"We are pretty excited about these results and the huge range of possible applications the technique might have, especially in the context of next-generation optical communications," said Dr Miro Erkintalo, whose work alongside colleagues Dr Stuart Murdoch, Associate Professor Stephane Coen and PhD student Jae Jan was published this week in open-access scientific journal Nature Communications.

"Our ability to move pulses around in time means we can reconfigure an optical data signal without the need for power-hungry, electronic conversion, which is what happens now.

"And with the tremendous pace at which the amount of optical data is growing, faster and more energy-efficient data processing will be needed sooner rather than later."

The work was supported by funding from the Marsden Fund through the Royal Society of New Zealand.