Conclusions and outlook
Microscopy

Microscopy is designed to produce enlarged images of transparent or reflective objects, with lateral and longitudinal resolutions that vary inversely with the magnification. Classically, when the microscope uses a true electromagnetic wave (light or X-rays) or one associated with moving particles (usually electrons), or a longitudinal propagating wave (acoustic), these resolutions are of the order of the wavelength if the image-forming systems are sufficiently well corrected for aberrations so that their quality is limited by diffraction. For near-field systems that do not obey classical diffraction laws, resolution depends essentially on the size and quality of the probe tip. The range of solutions available today (figure