DO EVANESCENT WAVES CONTRIBUTE TO THE FAR-FIELD

Evanescent waves have become of considerable interest in recent years because of developments in near-field optics. Claims have been made th at such waves contribute to the radiation fields of sources and to the far fields of scatterers. me show, by considering a spherical scalar wave and a linear electric dipole field, that these claims are mislead ing and that such contributions are without physical consequences. Our conclusions apply to a much broader class of fields than those consid ered in this Letter. (C) 1998 Optical Society of America.