White laser

Scientists Create White Laser:

The future of home lighting could be lasers No, we don’t mean those headache-inducing laser light shows they use to give people even more stimulation in clubs and parties. Instead, we’re talking about lighting every place in your home, from the living room to the kitchen to the bedroom. Apparently, that’s possible now after a team of scientists recently discovered how to produce white laser.

In a study conducted at Arizona University, a team of researchers showed how a new breed of semiconductor lasers can emit light across the full visible spectrum, producing the full-range of colors necessary to generate white laser. The team used a thin layer of semiconductor with three parallel segments, each one emitting one of the three elementary colors. Depending on how their output is tuned, this layer can produce any color in the spectrum that, when combined, produces laser that is pristine white.

Lasers are brighter and more energy-efficient than the existing LED standard, apart from providing more accurate and vivid colors, making them an ideal candidate for the next-generation of lighting.  While this is merely a first step towards using lasers in that capacity, it’s a significant one.  Previous attempts at producing white laser used multiple hardware, whose light outputs were combined, whereas the Arizona University team’s white laser emanated from a single unit, making it more feasible for mainstream use. The researchers point out that their white laser technology can prove beneficial in many applications, including “solid-state lighting, full-color displays, visible color communications, and multi-color fluorescence sensing.

Creating White Laser:

   Monolithic semiconductor lasers capable of emitting over the full visible-colour spectrum have a wide range of important applications, such as solid-state lighting, full-colour displays, visible colour communications and multi-colour fluorescence sensing. The ultimate form of such a light source would be a monolithic white laser. However, realizing such a device has been challenging because of intrinsic difficulties in achieving epitaxial growth of the mismatched materials required for different colour emission. Here, we demonstrate a monolithic multi-segment semiconductor nanosheet based on a quaternary alloy of ZnCdSSe that simultaneously lases in the red, green and blue. This is made possible by a novel nanomaterial growth strategy that enables separate control of the composition, morphology and therefore bandgaps of the segments. Our nanolaser can be dynamically tuned to emit over the full visible-colour range, covering 70% more perceptible colours than the most commonly used illuminants(from coolthings.com)