1. Different experimental configurations

In scanning tunneling electron microscopy, there is only one configuration. On the other hand, in near-field optical microscopy, numerous experimental configurations have been proposed and developed. Here, we present the main configurations to date.

First of all, as with traditional optical microscopy, a distinction must be made between microscopes that work by transmission and those that work by reflection. In transmission, light passes through the object, requiring transparent or sufficiently thin objects. Many potential applications involve non-transparent objects, and will require a reflection microscope.

But the specificity of near-field microscopes lies in the way the probe is used. There are three modes of operation: illumination, collection and perturbation.

In illumination mode, the probe is used as a nanosource...