The record-breaking lasers were created by physicists from Imperial College London in the UK and the Friedrich Schiller University Jena in Germany, using tiny wires made of zinc oxide placed on a silver surface.
“While the fastest lasers typically need several nanoseconds for one cycle our semiconductor nano-laser only needs less than a picosecond and is therefore a thousand times faster,“ said Carsten Ronning, one of the researchers involved from the Friedrich Schiller University Jena, in a press release.
“Turning a laser on and off quicker means more information carrying 1s and 0s per second, allowing much faster data communications. In fact, these lasers are so much faster than conventional electronics that we had to develop an optical switching method to measure their speed,” said lead author of the research Themis Sidiropoulos from the Imperial College London.
Traditionally in these types of semiconductor lasers, the nanowires are placed on a glass surface - but by using the silver surface they were able to speed up the light by “squeezing it”.
The zinc oxide nanowires are only 120 nanometres in diameter - around a thousandth of the diameter of a strand of human hair - and can already pulse out light at an impressive rate.
But by using features on silver called surface plasmons, which are wave-like motions of excited electrons found at the surface of metals, the physicists could squeeze the light into a much smaller space inside the laser, which meant that it also interacted more strongly with the zinc oxide nanowires.
This stronger interaction sped up the rate at which the lasers could be turned on and off by 10 times, and makes them the fastest on record.
"Most likely we also achieved the maximum possible speed, at which such a semiconductor laser can be operated,” said Robert Röder, a PhD student involved in the project in a press release.
The laser is also stable at room temperature, which makes it perfect for use in internet and communication systems. It could also be used to help detect single molecules or microbes in medical diagnostics.
“This work is so exciting because we are engineering the interaction of light and matter to drive light generation in materials much faster than it occurs naturally,” said senior author and Imperial College London researcher Rupert Oulton in a press release. “When we first started working on this, I would have been happy to speed up switching speeds to a picosecond, which is one trillionth of a second. But we’ve managed to go even faster, to the point where the properties of the material itself set a speed limit.”