Ultra-fast semiconductor nano-laser producing up to one trillion laser pulses per second has broken the world's laser speed record.
The device, developed jointly by German physicists from the University of Jena and British researchers from the Imperial College London, has been described in the latest issue of the Nature Physics journal.
“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 Professor Carsten Ronning from the University of Jena.
The team has built the laser using thin zinc-oxide wires, only a few hundreds of nanometres thick (about a thousandth of the width of a human hair) and a few micrometres long. Their properties make these nanowires an active laser medium and a resonator at the same time.
“Light is being reflected at the ends of the nanowire, similar to a mirror, and is then amplified while propagating through the nanowire,“ explained PhD researcher Robert Röder, one of the authors of the recent study.
Although the use of nanowires in lasers has been known before, the German-British research team has been the first to modify the speed of such nano-lasers by combining the semiconductor with a metallic layer leaving only a 10nm gap between the two in which the light field is constricted.
“This is how light-matter interactions are accelerated,“ Röder said, adding that the invention achieves more than only breaking the record in the laser switching speed.
“Most likely we also achieved the maximum possible speed at which such a semiconductor laser can be operated."
The team said the device could be used in building optical transistors and sensors for example to build extremely sensitive medical diagnostic devices.