Wavenumber ↩

Metadata

shorthands: {}
aliases: [Wave number, Repetency, Spatial frequency]
created: 2021-10-25 20:18:43
modified: 2022-01-10 04:13:03

The wavenumber is the spatial frequency of a wave, measured in radians per unit distance.
In physics it is usually used in wave equations. In this case, the following definition is useful:

Where is the wavelength of the wave.
In media with a given refractive index:

Where is the wavelength of light in a vacuum. This form also nicely works with complex refractive indices.

In spectroscopy

In spectroscopy, usually it is measured in cycles per unit distance, also called spatial frequency: