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Publication Citation: Optical microscope angular illumination analysis

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Author(s): Ravikiran Attota;
Title: Optical microscope angular illumination analysis
Published: March 07, 2012
Abstract: For high precision applications of optical microscopes, it is critical to achieve symmetrical angular illumination intensity at the sample plane, in addition to uniform spatial intensity achieved by Köhler illumination. In this paper, first we demonstrate a correlation between the contrasts in the image of a line grating target as the target is scanned through-the-focus, and the angular illumination asymmetry. Using this correlation we present a novel yet simple method of experimentally evaluating the angular illumination asymmetry (ANILAS) at the sample plane of an optical microscope across the field of view, which is called ANILAS map and is expected to be a useful method of assessing the illumination condition.
Citation: Optics Express
Keywords: Kohler illumination, angular illumination analysis, optical microscope,
Research Areas: Characterization, Nanometrology, and Nanoscale Measurements, Optical microscopy