Editing Transverse mode (section)

{{short description|Electromagnetic wave with oscillations perpendicular to the direction of travel}}
{{Redirect|Multi-mode|the communications technology|Multi-mode optical fiber}}
{{Refimprove|date=November 2009}}

A '''transverse mode''' of [[electromagnetic radiation]] is a particular [[electromagnetic field]] pattern of the radiation in the plane perpendicular (i.e., transverse) to the radiation's [[Wave propagation|propagation]] direction. Transverse modes occur in [[radio wave]]s and [[microwave]]s confined to a [[waveguide]], and also in [[light]] waves in an [[optical fiber]] and in a [[laser]]'s [[optical resonator]].<ref>[https://www.microwaves101.com/encyclopedias/transverse-electro-magnetic "Transverse electromagnetic mode"]</ref>

Transverse modes occur because of [[boundary condition]]s imposed on the wave by the waveguide. For example, a radio wave in a hollow metal waveguide must have zero tangential [[electric field]] amplitude at the walls of the waveguide, so the transverse pattern of the electric field of waves is restricted to those that fit between the walls. For this reason, the modes supported by a waveguide are [[quantization (physics)|quantized]]. The allowed modes can be found by solving [[Maxwell's equations]] for the boundary conditions of a given waveguide.