The first fiber laser was demonstrated over 50 years ago by E. Snitzer in a Neodymium doped fiber. Today, fiber lasers find many applications in different spheres f.e medical diagnostics, laser material processing, imaging, metrology, and scientific research. It is interesting to note how many advantages have fiber optics laser technology.
The fiber laser is the highest efficiency and power laser that can be used in different spheres. Fiber lasers are compact and rugged, don’t go out of alignment, and easily spend thermal energy. The fiber laser’s waveguides are unique. The inner active core is doped with a rare earth – like ytterbium, erbium, thulium and defines oscillation wavelength. It is surrounded by Fiber Bragg Gratings, which confines the pump light and couples it into the active core. Ultra-short pulse lasers can shape very precise microstructures and fabricate novel laser sources for industry. Fiber lasers support high beam quality at all the entire power range. In most common laser solutions, the beam quality is sensitive to output power. In fiber lasers, the output beam is virtually non-divergent over a wide power range. So, the beam can be concentrated to achieve high levels of precision, increased power densities and longer distances over which processing can be accomplished.
Usage of a fiber as a laser active medium allows prolonging interaction distance, which works well for diode-pumping. This geometry leads to high photon conversion efficiency, as well as a rugged and compact design. When novel fiber sources are joined together, there are no discrete optics to adjust or to get out of alignment.
The highest efficiency laser is highly adaptable. It can be adjusted to do anything from welding heavy sheets of metal to producing femtosecond pulses. Many variations exist on the fiber-laser theme. Fiber amplifiers provide single-pass amplification; they’re used in telecommunications because they can intensify many wavelengths in the meantime. Another example is fiber-amplified spontaneous-emission sources, in which the induced emission is suppressed. The Raman fiber laser is the another pattern, which is based on Raman gain that essentially Raman-shifts the wavelength. This is an application that’s not be practiced on a wide scale, but it certainly finds an application in research.
The market for the highest efficiency lasers is rapidly increased. Also seeing the substitution of non-fiber lasers with fiber lasers. The area of application fiber lasers now is an integral part of many photonic applications including biomedicine, material processing, astronomy and fundamental research. Nowadays, continuous wave fiber lasers with output powers above 1 kW become available. Fiber laser development still continues to be an active research field.
