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2004
Journal Article
Titel
Scaling single-mode photonic crystal fiber lasers to kilowatts
Abstract
Photonic crystal fiber lasers have the potential to revolutionize-earth-doped fiber lasers in high-power operation. The first rare-earth-doped fiber lasers, which produced a few milliwatts at a wavelength of around 1 µm, were operated in the early 1960s. For the next several decades, fiber lasers were little more than a low-power laboratory curiosity. Recently, however, with the advent of reliable, high-brightness, diode-pumped lasers and of double-clad fibers to facilitate coupling the pump light into the fiber they are entering the realm of kilowatt powers with diffraction-limited beam quality Compared with bulk solid-state lasers, the chief advantage of fiber lasers is their outstanding heat-dissipation capability, which is due to the large ratio of surface to volume of such a long, thin gain medium. As a result, thermal distortion of the beam is negligible, and the beam quality depends solely on the physical design of the fiber. Fiber lasers and amplifiers have a very high single-pass gain; therefore, low laser thres holds can be efficiently pumped with diode lasers. Moreover, the broad gain band width, and the compactness, robustness and simplicity of operation make fiber lasers attractive for a host of applications.