Diode lasers as comfortable for human eyes as LEDs

Washington, Oct 30 (ANI): Diode lasers can serve as the perfect alternative to LEDs, as both of them are equally comfortable for human eyes, a new study has suggested.

The tests, conducted at Sandia National Laboratories contradict the widespread assumption that human eyes would find laser-based white light unpleasant.

The experiment revealed that both the technologies pass electrical current through material to generate light, but the simpler LED emits lights only through spontaneous emission while the diode lasers bounce light back and forth internally before releasing it.

The finding is vital because LEDs, which are widely accepted as more efficient and hardier replacements for century-old tungsten incandescent bulb technology, lose efficiency at electrical currents above 0.5 amps.

However, the efficiency of the sister technology, the diode laser improves at higher currents, providing even more light than LEDs at higher amperages.

"What we showed is that diode lasers are a worthy path to pursue for lighting," Newswise quoted Sandia researcher Jeff Tsao, who proposed the comparative experiment, as saying.

For the tests, which took place at the University of New Mexico's Center for High Technology Materials, forty volunteers were seated, one by one, before two near-identical scenes of fruit in bowls, housed in adjacent chambers.

Each bowl was randomly illuminated by warm, cool, or neutral white LEDs, by a tungsten-filament incandescent light bulb, or by a combination of four lasers (blue, red, green, yellow) tuned so their combination produced a white light.

The experiment proceeded like an optometrist's exam where the subjects, who were not informed which source provided illumination, were asked about which picture did they prefer.

Each participant, selected from a variety of age groups, was asked to choose 80 times between the two changing alternatives.

The result showed that there was a statistically significant preference for the diode-laser-based white light over the warm and cool LED-based white light, Wierer said, but there was no statistically significant preference between the diode-laser-based and either the neutral LED-based or incandescent white light.

The research was published in the journal Optics Express. (ANI)