Light emission by magnetic and electric dipoles close to a plane dielectric interface II Radiation patterns of perpendicular oriented dipoles

Abstract

We have derived analytical expressions for the angular distribution P(α) of the power radiated by magnetic or electric dipoles located at distance z₀ from a dielectric interface and oriented perpendicular to it. For dipoles in the rarer medium very close to the interface, evanescent waves in the dipoles’ near field give rise to strong radiation into the denser medium. The resulting large maximum of P(α) shows characteristic differences for magnetic and electric dipoles when the relative refractive index of the two dielectrics is greater than √2. For dipoles lying on the interface a symmetry relation is established connecting the power distributions P(α) for the values n and 1/n of the relative refractive index.