intensity

plasmapy.formulary.laser.intensity(

electric_field_amplitude: Annotated[Quantity, Unit('V / m')],

) → Annotated[Quantity, Unit('W / m2')]

Calculate the intensity \(I\) of a laser from the electric field amplitude \(E_0\).

The intensity of an electromagnetic plane wave in vacuum is calculated using:

\[I=\frac{1}{2} c ε_0 E_0^2,\]

where \(c\) is the speed of light and \(ε_0\) is the permittivity of free space.

Aliases: I_

Parameters:

electric_field_amplitude (Quantity) – Electric field amplitude of an electromagnetic plane wave (convertible to V / m).

Returns:

Int – Intensity for the electric field amplitude provided.

Return type:

Quantity

Notes

For details, see Ling et al. [2016].

Examples

>>> import astropy.units as u
>>> intensity(0.8680211 * u.V / u.m)
<Quantity 0.001 W / m2>