On the Surface Fields Excited by a Hertzian Dipole Over a Layered Halfspace: From Radio to Optical Wavelengths

The Sommerfeld halfspace problem is revisited allowing for multilayer and plasmonic media, with a focus on the surface field computation. Alternative field representations are discussed and an improved Sommerfeld-Norton groundwave formula is developed. The role of the Zenneck wave and surface plasmon polariton in the surface field and their relationship is elucidated. The theoretical development is illustrated and validated by representative numerical results.