BOTHELL, Wash., Aug. 31 -- Aculight Corp., a developer of laser technologies, said it has produced an external cavity diode laser that combines the outputs from seven diode laser bars, each containing 200 single-mode emitters, to generate 26 watts of near-diffraction-limited light at 820 nm. The company said this may be the largest number of diode lasers combined into a single, high-beam-quality light source. "One of the most common lasers around is the diode laser," said Dennis Lowenthal, Aculight's vice president for research and development. "They're rugged, efficient and a great workhorse for generating optical power. But poor beam quality has limited their use in many applications. A technique called spectral beam combining, however, allowed us to merge the output of several diode laser bars yet retain the beam quality of a single emitter. The result is a novel high-power, high-quality diode source."
Spectral beam combining (SBC) is a power-scalable technique that overlays the outputs of many laser emitters into a single, near-diffraction-limited beam. Aculight said it originally developed the 820-nm laser for a military customer that needed to project a small spot of light on a faraway target using a highly efficient light source. However, the SBC technology behind the unique laser could provide an important stepping-stone for the use of diode lasers in many applications that demand high-power, high-beam-quality light, the company said, including laser projection displays, photodynamic therapy and as a pump source for fiber lasers.
"Until now, if I wanted to use diode bars to put light into a small optical fiber, or I wanted to shine the light a hundred miles away and still have a small beam, I couldn't really do that," said Lowenthal. "It's keeping them from being used as illuminators, or as pump sources for fiber lasers. Using SBC technology, we've added a few optical components to some diode bars and improved the optical quality by a factor of a thousand. All of a sudden we've created a rugged, efficient, high-quality light source that can be reproduced in any wavelength that diode lasers are available."
Aculight said it is working to bring SBC technology to market "and to eventually enable production of high-power laser sources with excellent beam quality at a lower cost per watt than is currently available."
The company presented a paper on the technology, "High Power Laser Source with Spectrally Beam Combined Diode Laser Bars, " at the 17th Annual Solid State and Diode Laser Technology Review conference, held in June in Albuquerque, N.M.
For more information, visit: www.aculight.com