A team of researchers at UC Santa Barbara led by Shuji Nakamura, winner of the 2006 Millennium Technology Prize, last week reported a major breakthrough in laser diode development.

The researchers, from the Solid State Lighting and Display Center in UCSB’s College of Engineering (COE), have achieved lasing operation in nonpolar gallium nitride (GaN) semiconductors, creating the world’s first nonpolar blue-violet laser diodes. They plan a public demonstration on campus at a date and place to be announced on the center’s Web site <www.ssldc.ucsb.edu>.

Nonpolar blue-violet laser diodes have numerous commercial applications, including high-density optical data storage for high definition displays and video, optical sensing, and medical applications. Because of the shorter wavelength of these devices, they can accommodate higher densities of optical storage than conventional red laser-based systems.

Nakamura, a professor of materials in the College of Engineering, is internationally known for his invention of revolutionary new light sources: blue, green, and white light-emitting diodes (LEDs) and the blue laser diode. He and two of his faculty colleagues, professors Steven DenBaars and James Speck, directed the work of two graduate students, Mathew Schmidt and Kwang Choong Kim, who fabricated the new nonpolar blue-violet laser diodes. The findings have now been submitted for publication.

Said Nakamura: “Our initial results of the first violet nonpolar laser diodes with a low threshold current density demonstrate a high possibility that current c-plane violet laser diodes used for HD-DVD and Blue Ray DVD could soon be replaced with nonpolar violet laser diodes, which require lower operating power and have longer lifetimes.”

Campus officials applauded the latest discovery. “This is a groundbreaking advancement in laser diodes and a major step in solid-state lighting technology,” said Chancellor Henry T. Yang, who visited the researchers’ laboratory minutes after hearing news of the exciting discovery.

Matthew Tirrell, dean of the COE, said he was proud that his colleagues are achieving breakthroughs “not only in solid state light sources for data storage and display systems, but also in energy efficient technologies that will have impact on people’s lives for decades to come.”