Fiber laser

A fiber laser or fibre laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, thulium and holmium. They are related to doped fiber amplifiers, which provide light amplification without lasing. Fiber nonlinearities, such as stimulated Raman scattering or four-wave mixing can also provide gain and thus serve as gain media for a fiber laser.

The advantages of fiber lasers over other types include:

Fiber laser can also refer to the machine tool that includes the fiber resonator.

Applications of fiber lasers include material processing (marking, engraving, cutting), telecommunications, spectroscopy, medicine, and directed energy weapons.

Unlike most other types of lasers, the laser cavity in fiber lasers is constructed monolithically by fusion splicing different types of fiber; fiber Bragg gratings replace conventional dielectric mirrors to provide optical feedback. Another type is the single longitudinal mode operation of ultra narrow distributed feedback lasers (DFB) where a phase-shifted Bragg grating overlaps the gain medium. Fiber lasers are pumped by semiconductor laser diodes or by other fiber lasers. Q-switched pulsed fiber lasers offer a compact, electrically efficient alternative to Nd:YAG technology.

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