Abstract
A small aperture or antenna can confine electromagnetic radiation to dimensions far smaller than the wavelength. Scanning such a structure in close proximity to an object can yield microscopic images with correspondingly high resolution. The benefit of using microwaves and millimeter-waves in scanning near-field microscopy lies in the promise of new types of material contrast. A good example is the mapping of electronic transport properties. In this review an overview of scanning near-field microwave, millimeter-wave, and submillimeter-wave microscopy is presented, a millimeter-wave microscope system using a slit-type probe is described in detail, and the application of this microscope for the visualization of photo-excited free carriers in a silicon substrate is demonstrated.
