BOTHELL, Wash., July 14 -- Aculight Corp. announced it has produced a 60-watt, 540-nm, frequency-doubled, large mode area (LMA) fiber laser system. The company said the system could enable the use of fiber lasers in applications that demand high-power green laser output such as materials processing, large-area displays and medical and military imaging. Aculight described the system in a paper at the 17th Annual Solid State and Diode Laser Technology Review (SSDLTR) conference held last month in Albuquerque, N.M. The company said its engineers initially developed the technology to satisfy the demands of a military customer. Although they considered modifying conventional diode-pumped solid-state (DPSS) laser technology, they instead chose to create a groundbreaking fiber laser system. "There was an opportunity to leapfrog beyond the existing technologies to something that had even higher performance in all of the dimensions that our customer wanted," said Roy Mead, Aculight vice president. "It involved working with LMA fibers." Aculight's system centers on an ytterbium-doped LMA fiber amplifier capable of achieving high average power, while allowing substantial peak power without the onset of nonlinear effects -- characteristics essential for efficient frequency doubling. In the system, a seed laser source consisting of a 1080-nm CW fiber oscillator, an amplitude modulator and a preamplifier provides input pulses to the LMA amplifier. The amplifier fiber is wound onto a small mandril to promote good transverse mode quality and polarization purity, and pumped at the output end by free-space coupling optics. The amplifier output is then directed into a pair of LBO crystals. The new system could mark an important step toward deploying green, high-power fiber lasers in the many military and commercial systems that now rely on DPSS and argon-ion lasers, Aculight said. "Today's green laser marketplace is dominated by DPSS and argon-ion lasers that produce less than 20 watts, or function at moderate repetition rates," said Mead. "Our new system surpasses those performance characteristics and will likely extend past the 60 watts that we've achieved so far. And the techniques we've used to wavelength convert can apply to a variety of fiber systems, so will also allow us access to a wide range of wavelengths. This LMA fiber system really fits into a different region of the product space." Aculight said it plans to further develop its LMA fiber laser technology so that it can be made commercially available. The paper presented at the SSDLTR conference was entitled, "60-Watt Output at 540-nm from a Frequency Doubled LMA Fiber Laser System." For more information, visit: www.aculight.com