Restricting the delivery of power to a laser, such as those used in CD players and military surveillance, could significantly boost its output.

The discovery could lead to ultra-sensitive and energy-efficient lasers and allow researchers to have more control over their frequencies and spatial pattern of light emission, Princeton University reported.

"It's as though you are using loss to your advantage," said study author and graduate student Omer Malik.

When delivery of power to the lasers is restricted much of the physical space within is absorbed instead of working to create light, but this also frees it from competition with less efficient portions. The method is predicted to result in an improvement in light output even greater than researchers had previously estimated. To make these findings the research team used mathematical calculations and computer simulations, but have not yet tested it out in an actual laser.

"Distributing gain and loss within the material is a higher level of design - a new tool - that had not been used very systematically until now," said Hakan Tureci, assistant professor of electrical engineering at Princeton.

The finding could lead to more portable laser devices with applications in medical diagnostics and bomb-detection. The recent predictions offer insight into the "fundamental processes that govern how lasers produce light," Princeton reported.

In the past researchers have worked to improve laser performance by either trying out new materials or changing the physical shape of the device; this new method of controlling power gains and losses in certain regions of the laser offers a third approach.

The findings were published Oct. 26 in the journal Nature Photonics. Funding for the research came from the National Science Foundation through the Mid-Infrared Technologies for Health and the Environment center based at Princeton. Additional funding came from the Defense Advanced Research Projects Agency.