Enhancement of wire diameter measurements: Comparison between Fraunhofer diffraction and Lorenz-Mie theory


LEBRUN D., BELAID S., Ozkul C. , REN K., GREHAN G.

OPTICAL ENGINEERING, vol.35, no.4, pp.946-950, 1996 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 35 Issue: 4
  • Publication Date: 1996
  • Doi Number: 10.1117/1.600703
  • Title of Journal : OPTICAL ENGINEERING
  • Page Numbers: pp.946-950

Abstract

The Fraunhofer diffraction is compared with a numerical simulation based on the Lorenz-Mie theory to improve the performance of a laser diffraction instrument. This instrument, based on the analysis of diffraction fringes at the focal plane of a lens, is especially suitable for individual wire diameter measurements. We show that the error due to Fraunhofer approximation increases with an increase of the reflectivity and a decrease of the object diameter. Comparison with Lorenz-Mie theory enables us to correct these errors. For a given object, the laser diffraction instrument reproduces diameter measurements with a very small dispersion. (C) 1996 Society of Photo-Optical instrumentation Engineers.