| an asymptotic model for wavelengths approaching zero by which the propagation of waves, in various media and at their boundaries is determined by using the geometrical concept of rays and not the general theory of waves
NOTE 1 – Polarization of waves is generally not taken into account by geometrical optics.
NOTE 2 – For geometrical optics to be applicable in practice, the following conditions are required:
a) The space variations of the electrical properties of the various media must be small along a distance of one wavelength.
b) The surface separating two different media must be very large and its irregularities very small with respect to wavelength.
c) The grazing angle of a wave on a surface separating two different media must not be too small.