Editing Radiation angle (section)

{{short description|Half the vertex angle of the cone of light emitted at the exit face of an optical fiber}}
{{more citations needed|date=February 2022}}
In [[fiber optics]], the '''radiation angle'''<ref>{{Cite web|title=Radiation angle {{!}} antennas and accessories|url=https://interline.pl/Information-and-Tips/Radiation-angle|access-date=2022-02-22|website=interline.pl}}</ref> is half the [[vertex angle]] of the cone of [[light]] emitted at the exit face of an [[optical fiber]].

The cone boundary is usually defined (a) by the angle at which the [[far-field]] [[irradiance]] has decreased to a specified fraction of its maximum value or (b) as the cone within which there is a specified fraction of the total radiated [[Power (physics)|power]] at any point in the [[far field]].