Lasers are celebrating the 50 anniversary of the invention celebrations, and the American inventor of fiber lasers, Eliassnitzer, is now perhaps fit to discuss why fiber lasers are so different from other types of lasers. Solid-State lasers and fiber lasers use one of many rare earth elements as active media for producing laser beams.
The name "rare earths" stems from the fact that they were found to be extremely scarce. Many parts of the world do produce minerals because many of the current reserves are located in Inner Mongolia, China, and there are some supply concerns. These rare earth elements complement the last two lines of the periodic table. For many people outside the laser industry, these 15 elements are not easy to pronounce and may not be fully spelled, they belong to the lanthanum element because of its chemical properties similar to that of the element lanthanum. The most widely used Rare-earth active element in fiber lasers is ytterbium, named after Sweden's small village, where a large number of such rare earths and many other Rare-earth minerals have been discovered for the first time near the small village. Ytterbium is a complex electronic structure, which can effectively generate coherent neutrons when it is carefully distributed within the core active fibers of the laser.
