Image Formation in the Scanning Microscope

TLDR

Fourier imaging in scanning microscopes reveals two geometries: Type 1, which behaves like conventional microscopes, and Type 2 (confocal), which exhibits distinct imaging characteristics. The study examines point‑object imaging, two‑point resolution, edge response, and the influence of annular‑pupil lens arrangements on microscope performance. Type 2 confocal microscopes outperform conventional designs, and their imaging can be further enhanced by incorporating one or two annular‑pupil lenses.

Abstract

Fourier imaging in the scanning microscope is considered. It is shown that there are two geometries of the microscope, which have been designated Type 1 and Type 2. Those of Type 1 exhibit identical imaging to the conventional microscope, whereas those of Type 2 (confocal microscopes) display various differences. Imaging of a single point object, two-point resolution and response to a straight edge are also considered. The effect of various arrangements using lenses with annular pupil functions is also discussed. It is found that Type 2 microscopes have improved imaging properties over conventional microscopes and that these may be further improved by use of one or two lenses with annular pupils.