SURFACE ENHANCEMENT OF LOCAL OPTICAL EFFE CTS AND LIGHTNING-ROD EFFECT

Enhancement of the local field E(loc) by the ''lightning-rod'' effect is studied theoretically (on the model of small ellipsoid) and experim entally (by means of the surface-enhansed second-harmonic generation m ethod on the surfaces with protruding needles). The algorythm of separ ating the general electromagnetic enhancement onto resonant and nonres onant components both on the model and in the experiment is suggested. The limitation of the nonresonant local field enhancement by the diel ectric constant of metal was discovered on the model and approved by t he experiment.