Researchers have recently discovered that being able to restrict the delivery of power to a laser, like those used in CD players and military surveillance, could play a vital role in significantly boosting its output. The discovery has paved a way for the development of ultra-sensitive and energy-efficient lasers and enable researchers to gain more control over their frequencies and spatial pattern of light emission, reported Princeton University.

Study author and graduate student Omer Malik said that it won't be wrong to say that it's a use of loss to advantage. Engineers at Princeton University have been able to restrict the delivery of pump energy to selected areas within a laser. This allowed functioning of certain higher-order modes, and not the usual lower-order modes.

According to the researchers, much of the physical space within a laser absorbs light rather than producing once the delivery of power is restricted. As a result, the optimally efficient portions of the laser is freed from competition with less efficient portions and lasers far more brightly than what has been suggested by previous estimates.

"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.

Previous studies were only based on applying electric current to the part of the laser that first reaches threshold, which enabled to lower the overall amount of power required to get the laser to turn on. The constraint with these studies was not taking the full range of modes under consideration. Also, they did not describe how brightness and efficiency could be controlled by targeting the delivery of current.

Tureci said the recent stint has showed that once a laser is built with the fine-grained electrical connections capable of allowing this targeting, its performance can be controlled on the fly, not just during fabrication.