A small laser could be the key to increasing the amount of data storage on compact disks if Peidong Yang, a professor of chemistry at the University of California in Berkeley, has his way. His laser, which is one thousand times thinner than a human hair, is also said to be an alternative to today’s solid state lasers made from gallium arsenide and gallium nitride. Instead, Yang uses zinc oxide. He paints a gold catalyst onto a sapphire and places it in zinc oxide. The gold forms the crystal wires, which are hexagonal in cross section. The arrays of wire resemble hairbrush bristles. They emit UV light from their flat tips, which act like mirrors. The ends attached to the semiconductor also act like mirrors. Light emitted by the zinc oxide bounces back and forth, causing emission and amplification of the light. Yang uses optical pumping for exciting the zinc-oxide molecules. “Optical pumping uses a conventional laser for exciting our nanowire sample, so that stimulated emission can be generated from the nanowires,” explains Yang. “One of the next steps in commercializing the nanolaser is its successful integration as a miniaturized light source in optoelectronic applications,” he says. For more information, contact Yang at (510) 643-1545 or go to www.cchem.berkeley.edu.
This year, Design News is getting a head start on the Fourth of July celebration. In honor of our country and its legacy of engineering innovation -- in all of its forms -- we are taking you on an alphabetical tour through all 50 states to showcase interesting engineering breakthroughs and historically significant events.
Earlier this year paralyzed IndyCar drive Sam Schmidt did the seemingly impossible -- opening the qualifying rounds at Indy by driving a modified Corvette C7 Stingray around the Indianapolis Motor Speedway.
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