Vacuum wavelength

Description

When an electromagnetic wave travels through a medium in which it gets attenuated (this is called an “opaque” or “attenuating” medium), it undergoes exponential decay as described by the Beer–Lambert law. However, there are many possible ways to characterize the wave and how quickly it is attenuated.

For a given frequency, the wavelength of an electromagnetic wave is affected by the material in which it is propagating. This equation gives the vacuum wavelength (the wavelength that a wave of this frequency would have if it were propagating in vacuum).