Wave Vector

The wavevector refers to a vector that describes the phase variation of a plane wave, in 3-orthogonal directions (x, y, and z-axes typically). The magnitude of the wavevector is the wavenumber. For a wave propagation in a direction described by the spherical coordinates , the wavevector k is given by: The x-component of the wavevector, , determines the rate of change of the phase of a propagating plane wave in the +x-direction. The same definitions apply for the y- and z-directions.