Encyclopedia … combined with a great Buyer's Guide!

Sponsors:     and others

Core-less End Caps

Definition: end pieces attached to optical fibers, containing no fiber core

Categories: fiber optics and waveguides, laser devices and laser physics

How to cite the article; suggest additional literature


URL: https://www.rp-photonics.com/core_less_end_caps.html

For some fiber optics applications, particularly in the area of fiber amplifiers and lasers, it can be helpful to use optical fibers with core-less end caps. These end caps are essentially homogeneous transparent pieces with a length of a few millimeters, for example. As the end caps contain no waveguide (fiber core), light propagates in these regions as beams which expand toward the ends.

core-less end cap
Figure 1: A fiber with core-less end cap. A beam from air is adjusted such that its focus is where the waveguide structure in the fiber begins.

Such end caps can be made by attaching (e.g. fusion splicing) small pieces of homogeneous glass to the fiber ends. In case of photonic crystal fibers, it can be sufficient to heat the fiber end e.g. with a fusion splicer, so that the microscopic holes collapse.

The possible advantages of core-less end caps are:

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.

Your question or comment:

Spam check:

  (Please enter the sum of thirteen and three in the form of digits!)

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.


[1]Y. O Aydin et al., “Endcapping of high-power 3 μm fiber lasers”, Opt. Express 27 (15), 20659 (2019), doi:10.1364/OE.27.020659

(Suggest additional literature!)

See also: fibers, fiber lasers, fiber amplifiers, photonic crystal fibers, fiber optics
and other articles in the categories fiber optics and waveguides, laser devices and laser physics


If you like this page, please share the link with your friends and colleagues, e.g. via social media:

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