Filament efficiency

Researchers at the University of Rochester, New York, have developed a laser-based process that could reduce the power consumption of incandescent light bulbs.

The process could make a light as bright as a 100W bulb consume less electricity than a 60W bulb, while remaining far cheaper and radiating a more pleasant light than a fluorescent bulb.

The laser process creates an array of nano- and micro-scale structures on the surface of a regular tungsten filament - the wire inside a light bulb - and these structures make the tungsten become far more effective at radiating light.

'We've been experimenting with the way ultra-fast lasers change metals, and we wondered what would happen if we trained the laser on a filament,' said Chunlei Guo, associate professor of optics at the university.

'We fired the laser beam right through the glass of the bulb and altered a small area on the filament.

'When we lit the bulb, we could actually see this one patch was clearly brighter than the rest of the filament, but there was no change in the bulb's energy usage.'