New laser captures energy like noise-cancelling headphones

ANU researchers Kirill Koshelev and Yuri Kivshar. Physicists at The Australian National University (ANU) have developed extremely powerful microscopic lasers that are even smaller than the wavelength of the light they produce. So called 'nanolasers' have a huge variety of medical, surgical, industrial and military uses, covering everything from hair removal to laser printers and night-time surveillance. According to lead researcher Professor Yuri Kivshar, the nanolasers developed by his team promise to be even more powerful than existing lasers, allowing them to be useful in smaller-scale devices.  "They can also be integrated on a chip," he said.  "For example, they can be mounted directly on the tip of an optical fibre to lighten or operate on a particular spot inside a human body.  "This technology uses laser light instead of electronics, an approach called photonics. It's exciting to see how this can be realised in everyday practical devices, like mobile phones."   Professor Kivshar's team used a clever trick to modify conventional lasers, which traditionally comprise some form of light amplification device placed between two mirrors.  As the light bounces back and forth between the two mirrors it becomes brighter and brighter. Instead of mirrors, the research team created a device that works like "inside-out" noise-cancelling headphones and which traps energy and prevents it from escaping. The trapped light energy builds up into a strong, well-shaped laser. This trick overcomes a well-known challenge of nanolasers - energy leakage.