| a complex vector which characterizes a sinusoidal electromagnetic wave relative to a point in space when each of the electromagnetic field vectors can be represented, in a domain of space in the neighbourhood of this point, by an expression such as:|
- vectors , generally complex, are independent of time and practically constant in the domain considered,
- vector is practically constant in the domain considered,
- ω is the angular frequency,
- t is time,
- is the vector joining the origin of coordinates to the point of interest in the domain
NOTE 1 – If the wave can be characterized by a wave vector at every point in a domain, there exists a wavefront containing the point and orthogonal to the real part of the wave vector. The magnitude of is 2π divided by the wavelength.
NOTE 2 – The wave has an elliptical polarization if the imaginary part of each vector is neither zero nor collinear with its real part; the wave has a linear polarization in the other cases.