Can lasers save the incandescent light bulb?

A new breakthrough this week may change the attitude that the incandescent light bulb has had it's day.

Compact fluorescent bulbs (CFLs) have unquestionably gained popularity for their energy efficiency when compared to the traditional incandescent light bulb. Millions of people around the world have been encouraged bypoliticians, governments, energy utilities, and even light bulb companies themselves to phase out traditional incandescent bulbs in favor of CFLs (or even LEDs) to save electricity in the home.

But now researchers at the University of Rochester in New York have found a way to make an incandescent light bulb more efficient.

Chunlei Guo, associate professor of optics at the University of Rochester.

(Credit: University of Rochester)

A group led by Chunlei Guo, associate professor of optics at the University of Rochester, has been testing the effects of ultra-fast lasers on the properties of metals and decided to try a tungsten filament (the tiny wire you see in the average light bulb).

The group blasted the tungsten filament with an ultra-fast short-pulse laser for a femtosecond. A femtosecond is to a second "what a second is to about 32 million years," according to the researchers.

The blast changed the properties of the surface metal on the filament so that it formed nanostructures and microstructures that enabled it to shine significantly more brightly while still using the same amount of electricity.

"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," Guo said in a statement.

The change in the filament has enabled the incandescent light bulb to shine as bright as an average 100-watt bulb, but consume less electricity than the average 60-watt bulb.

Full details of the project, which was sponsored by the U.S. Air Force Office of Scientific Research, will be published in the next issue of "Physical Review Letters."

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