LIGHT-SCATTERING DESCRIBED IN THE MODE PICTURE

A system of orthonormal functions representing the eigenmodes of an op tical resonator with perfectly spherical mirror surfaces has been desc ribed in the literature. In real experiments, however, the wave front of the passing beam will be deformed by surface irregularities or inde x inhomogeneities inside components traversed by the beam. We describe quantitatively the relative power transferred out of the fundamental mode into higher-order modes by these irregularities.