Correction to Microscopically Determined Particle Size According to Diffraction Correction Theory

Measuring Particle Diameter and Particle−Particle Gap with Nanometer Precision Using an Optical Microscope

“…The diffraction images of two touching or almost-touching particles appear as two Airy patterns, which consist of a central Airy disk surrounded by several diffraction rings . The diffraction rings can be treated using Fraunhofer diffraction 7 principles, as the theory of diffraction for circular phase objects can also be applied to spherical objects (at least, for the PS latex spheres) . Thus, in principle, it might be possible to size individual colloidal spheres (i.e., not doublets) from their Airy patterns, although we do not pursue such an approach in this paper.…”

“…7 The diffraction rings can be treated using Fraunhofer diffraction 7 principles, as the theory of diffraction for circular phase objects can also be applied to spherical objects (at least, for the PS latex spheres). 8 Thus, in principle, it might be possible to size individual colloidal spheres (i.e., not doublets) from their Airy patterns, although we do not pursue such an approach in this paper. Rather, the key in our experiments is to determine the locations of the central Airy disks of the two touching spheres (Figure 1c).…”