Researchers, led by an Indian-origin scientist, have developed a new polarizing filter that allows in more light, paving way for efficient LCD display and cameras that can shoot in dim light.
Polarizers are indispensable in digital photography and LCD displays, but they block enormous amounts of light, wasting energy and making it more difficult to photograph in low light.
The researchers at the University of Utah created the filter by etching a silicon wafer with nano-scale pillars and holes using a focused gallium-ion beam.
This new concept in light filtering can perform the same function as a standard polarizer but allows up to nearly 30 per cent more light to pass through, said electrical and computer engineering associate professor Rajesh Menon.
Polarizers are widely used by photographers, for example, to reduce glare in the image. They also are used in LCD displays to regulate what light passes through to create images on the screen.
"When you take a picture and put the polarized filter on, you are trying to get rid of glare. But most polarizers will eliminate anywhere from to 60-70% of the light. You can see it with your eyes," Menon said.
With Menon's new polarizer, much of the light that normally is reflected back is instead converted to the desired polarized state, he said. The researchers have been able to pass through about 74 per cent of the light, though their goal is to eventually allow all of the light to pass through.
LCD displays on devices such as smartphones and tablets have two polarizers that ultimately throw away most of the light when working with the liquid crystal display. "If one can increase that energy efficiency, that is a huge increase on the battery life of your display. Or you can make your display brighter," Menon said.
Menon's team validated their concept using a polarizer that is only 20 by 20 micrometres and tested with only infrared light.
But they plan to increase the size of the filter, use it with visible light, and figure out a way to make it more cost effective to manufacture.
Menon said the first marketable applications of this technology could be available in five to 10 years.
The technology also could be a boon for photographers who want to bring out more detail in their pictures while shooting in low-light situations and for scientists using microscopes and telescopes to visualize obscure phenomenon.
The study was published in the journal Optica.