ABSTRACT
The meaning and importance of optical near field phenomena can be studied in the framework of general optical processes, such as a light-scattering pro cess involving two atomic-scale objects, i.e., the sample and probe [1],
An incident light wave drives an effective field both inside and outside the sample. For observation of the effective field near the sample, the fol lowing two requirements have to be met:
1 The probe must have dimensions as small as the sample (this require ment determines the penetration depth of the effective field, since the effective field corresponds to the electromagnetic correlation produced in the sample itself);
2 The probe tip must be placed near the sample, where an effective field with a short penetration depth maintains its significance.
