Encyclopedia … combined with a great Buyer's Guide!

End Pumping

Definition: a technique of optically pumping a laser medium in a direction along the laser beam

Opposite term: side pumping

German: Endpumpen

Categories: laser devices and laser physics, methods


Cite the article using its DOI: https://doi.org/10.61835/ona

Get citation code: Endnote (RIS) BibTex plain textHTML

End pumping (also sometimes called longitudinal pumping) of lasers and optical amplifiers is a technique of optically pumping a laser gain medium, where the pump light is injected along the laser beam, rather than in a transverse direction (side pumping).

end-pumped laser
Figure 1: Setup of a typical end-pumped solid-state laser.

The geometry of end pumping often allows one to achieve a good spatial overlap between pump and laser radiation. That in turn can have multiple benefits:

For these reasons, most diode-pumped solid-state lasers, particularly those with lower output powers, are end-pumped.

There are also various potential disadvantages of end pumping:

  • Pump light can be injected only from at most two directions, and that may limits the applicable total pump power.
  • Particularly for pumping a long laser crystal with a small beam radius, one requires a pump source with high beam quality, or in combination with a certain level of optical power a high radiance (brightness). Therefore, lamp-pumped lasers, for example, can usually not be end-pumped.
  • The optical intensity and the crystal temperature vary along the beam direction – particularly for unidirectional pumping, but substantially less for bidirectional pumping.

Due to these limitations, end pumping often cannot be used for high-power lasers, and in particular not for lamp-pumped lasers. There are techniques, however, to extend the end pumping concept to fairly high powers; for example, multi-segmented rods (→ composite laser crystals) can be used for better distributing the absorbed power.

See also: optical pumping, lasers, solid-state lasers, side pumping, laser gain media, beam quality, spotlight 2007-04-01

Questions and Comments from Users

Here you can submit questions and comments. As far as they get accepted by the author, they will appear above this paragraph together with the author’s answer. The author will decide on acceptance based on certain criteria. Essentially, the issue must be of sufficiently broad interest.

Please do not enter personal data here; we would otherwise delete it soon. (See also our privacy declaration.) If you wish to receive personal feedback or consultancy from the author, please contact him, e.g. via e-mail.

Spam check:

By submitting the information, you give your consent to the potential publication of your inputs on our website according to our rules. (If you later retract your consent, we will delete those inputs.) As your inputs are first reviewed by the author, they may be published with some delay.


Share this with your friends and colleagues, e.g. via social media:

These sharing buttons are implemented in a privacy-friendly way!