New fiber laser technology
December 8--Technology developed at Femlight and University of Jena opens a new field of applications in between solid-state and fiber lasers.
December 8--Taking advantage of the best of both worlds, scientists at Femlight (Talence, France) and the University of Jena (Jena, Germany) have used a rod-type fiber laser to overcome limits of conventional solid-state and fiber lasers. The scientists explain that, on the one hand, diode-pumped solid-state lasers can produce energetic pulses but the beam quality degrades quickly as soon as the average power increases. On the other hand, fiber lasers are capable of producing high CW average powers with diffraction-limited beam but do not sustain the energy needed for industrial applications where short pulses are used.
Using a new generation of photonic fibers in a special resonator configuration, these scientists have been able to demonstrate a 280kW peak power Q-switched laser with 8.5ns/2.4mJ pulses at repetition rates adjustable from 1 to 100 kHz. The diode-pumped fiber laser provided average powers up to 100 W in a diffraction-limited beam, with more than 41 percent optical-to-optical efficiency. They claim the combination of high average power, short pulses, high peak power, and excellent beam quality make this laser a perfect candidate for multiple industrial applications from flat panel display patterning to deep engraving.
According to Francois Salin, Femlight's CTO, "This new technology opens a completely new field of applications in between solid-state lasers and fiber lasers with basically a very simple cavity configuration and a great potential for extraordinary performances. We expect the average power to reach 200 W in 2006 and 1 kW in 2007." Femlight will introduce the first product based on this technology at Photonics West in January. Additionally, more product running in the visible (515 nm) or in the UV (343 nm) is expected to follow quickly.