A fiber disk laser is a

fiber laser A fiber laser (or fibre laser in Commonwealth English) 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 ar ...

with transverse delivery of the

pump A pump is a device that moves fluids (liquids or gases), or sometimes Slurry, slurries, by mechanical action, typically converted from electrical energy into hydraulic or pneumatic energy. Mechanical pumps serve in a wide range of application ...

light. They are characterized by the pump beam not being parallel to the active core of the

optical fiber An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...

(as in a

double-clad fiber Double-clad fiber (DCF) is a class of optical fiber with a structure consisting of three layers of optical material instead of the usual two. The inner-most layer is called the ''core''. It is surrounded by the ''inner cladding'', which is surr ...

), but directed to the coil of the fiber at an angle (usually, between 10 and 40 degrees). This allows use of the specific shape of the pump beam emitted by the

laser diode file:Laser diode chip.jpg, The laser diode chip removed and placed on the eye of a needle for scale A laser diode (LD, also injection laser diode or ILD or semiconductor laser or diode laser) is a semiconductor device similar to a light-emittin ...

, providing the efficient use of the pump.

Realizations of fiber disk lasers

First disk lasers were developed in the Institute for Laser Science, Japan. Several realizations of fiber disk lasers were reported. The fiber disk laser is so named because the fiber is tightly coiled. Typically, no special feedback for the laser frequency is required, as the small reflection at end of the fiber is sufficient to provide efficient operation. In this case, both ends of the coiled fiber can be used as output.

Application and power scaling

Fiber disk lasers are used for cutting of metal (up to few mm thick),

welding Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the parts together and allow them to cool, causing Fusion welding, fusion. Co ...

and

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. The disk-shaped configuration allows efficient heat dissipation (usually, the disks are cooled with flowing water), allowing

power scaling Power scaling of a laser is increasing its output power without changing the geometry, shape, or principle of operation. Power scalability is considered an important advantage in a laser design. This means it can increase power without changing outs ...

. When the increase of the length of the fiber becomes limited by

stimulated scattering "Stimulated" (stylized as "$timulated") is a song by American rapper Tyga, and the fifth single from his mixtape '' Fuk Wat They Talkin Bout'' (2015). It was produced by Crakwav and uses a sample of "Children" by Robert Miles. The song is a respon ...

, additional power scaling can be achieved by combining several fiber disk lasers into a stack. The spiral-coiled configuration is not the only possible arrangement; any other scheme of stacking of optical fibers with lateral delivery of pump can also be called a fiber disk laser, even if the resulting shape of the device is not circular. The term ''fiber disk laser'' applies to the concept of lateral delivery of pump to the active optical fiber rather than specifically to a disk-shaped device. The optimal shape of the fiber disk laser may depend on the properties of the beam of pump available, as well as on the specific application.

References

External links

* http://www.nature.com/nphoton/journal/vsample/nsample/full/nphoton.2006.6.html
IEEE
*http://sciencelinks.jp/j-east/article/200705/000020070506A1021450.php {{Webarchive, url=https://web.archive.org/web/20110716234814/http://sciencelinks.jp/j-east/article/200705/000020070506A1021450.php , date=July 16, 2011 Solid-state lasers Fiber optics