Measurement of the Diameter of Opaque Cylinders by Scanning Microscopy

Abstract

Experiments have been carried out to determine the systematic errors in the measurement of the diameters of opaque cylinders by scanning microscopy. It was found that for cylinders of diameter near the optical resolution limit, the scanning microscope gives too large a size estimate. The variation of the error with aberrations and numerical aperture of the scanning objective, and with the wavelength and state of polarization of the light were determined. Optimum conditions for size determination are suggested.