Scientists have created the smallest-ever laser to work at room temperature, as well as one that doesn't waste a single photon.
The University of California, San Diego researchers say the two new lasers require very low power to operate - an important breakthrough, as lasers usually require more and more 'pump power' to get started, the smaller they become.
They could be very useful components for future optical circuits packed on to tiny computer chips, says the team. Other applications could include tiny biochemical sensors or high-resolution displays.
The thresholdless laser could also help in the development of new metamaterials for applications from super-lenses that can be used to see individual viruses or DNA molecules to optical cloaking devices.
To overcome the 'pump power' problem, the researchers developed a design that uses quantum electrodynamic effects in coaxial nanocavities. The resulting room-temperature nanoscale coaxial laser is less than half a micron across.
The designs appear to be scalable, says the team – meaning that they could be shrunk to even smaller sizes.
The researchers says they're still working out the theory behind how the tiny lasers operate. They're also looking for a way to pump the lasers electrically instead of optically.