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5 December 2013 11:26 am ,
Vol. 342 ,
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Blue Lasers Power Up
16 September 1999 7:00 pm
Blue and red lasers are both typically made of a layered semiconductor that gives off photons. The light escapes from one edge of the thin chip, which makes it difficult to generate a bright beam. Scientists solved this problem for red lasers by creating many tiny lasers that shine from the flat surface of the chip. "The value of this type of laser is that it emits light in pixels," says Eric Tournié, a physicist with the Centre National de Recherche Scientifique near Valbonne, France.
Now a team led by Takao Someya of the University of Tokyo in Japan has duplicated the feat in blue. To create their laser array, the team first deposited a series of alternating layers--called a multilayer--of gallium nitride and aluminum nitride on a small sapphire chip. As they describe in tomorrow's issue of Science, the researchers then drilled with holes just 10 micrometers wide. After filling these cavities with semiconducting material, Someya and his crew capped the chip with another multilayer.
The semiconducting filling is blasted by another laser, whose photons have the necessary energy to create blue photons from the material. These blue photons bounce between the multilayers, producing other photons. Once enough are flying back and forth, photons begin to escape through the top layer and the laser is in action.
Because the blue laser's photons have a shorter wavelength than those in red lasers, they can detect much smaller pits or bumps in CDs or other storage media. And that means more music or information packed into a smaller space.