RP Photonics logo
RP Photonics
Encyclopedia
Technical consulting services on lasers, nonlinear optics, fiber optics etc.
Profit from the knowledge and experience of a top expert!
Powerful simulation and design software.
Make computer models in order to get a comprehensive understanding of your devices!
Success comes from understanding – be it in science or in industrial development.
The famous Encyclopedia of Laser Physics and Technology – available online for free!
The ideal place for finding suppliers for many photonics products.
Advertisers: Make sure to have your products displayed here!
… combined with a great Buyer's Guide!
VLib part of the
Virtual
Library

Cavities

<<<  |  >>>

Definition: resonators for light (or for microwaves)

German: Kavitäten, Resonatoren

Categories: general optics, optical resonators

How to cite the article; suggest additional literature

Optical resonators are often called cavities. This term has been taken over from microwave technology, where resonators really look like closed cavities, whereas optical resonators normally have an “open” kind of setup. That difference in geometry is related to the fact that optical resonators are usually very large compared with the optical wavelength, whereas microwave cavities are often not much longer than a wavelength.

Only so-called optical microcavities have dimensions in the micrometer or even sub-micrometer regime, and can tightly enclose a light field in all directions. Microcavities can be realized e.g. with tiny semiconductor or glass structures, such as microtoroids, or as defect structures in photonic crystals.

Even though the term “cavity” is often not completely appropriate, as explained above, many related terms are based on it. Examples are laser cavities (laser resonators), cavity dumping and cavity design (resonator design).

The two basic types of cavities are:

The article on optical resonators contains more details.

See also: optical resonators, resonator design, resonator modes, stability zones, reference cavities, free spectral range, finesse, bandwidth, Q factor
and other articles in the categories general optics, optical resonators

If you like this article, share it with your friends and colleagues, e.g. via social media:

arrow