Optics: measuring and testing – By dispersed light spectroscopy – Utilizing a spectrometer
Patent
1997-03-20
1998-07-21
Turner, Samuel A.
Optics: measuring and testing
By dispersed light spectroscopy
Utilizing a spectrometer
2502013, G01B 902
Patent
active
057841640
ABSTRACT:
A method and improved system for automatically and substantially simultaneously focusing and orienting an interferometric optical system, such as an interferometric microscope (25) illuminated by broad-band light, with regard to a surface under test (66), for providing a best focus and orientation of objects to be measured. The optical system (20, 25, 30, 35, 37, 60, 40) includes a pixel array, such as a sparse array (30) onto which an interferogram is imaged. The pixel array (30) is scanned (20, 25) for detecting a peak fringe contrast for the pixels in the array (30) and the scan position at the detected peak fringe contrast for each pixel int he array (30) is saved (40). At least a portion, if not all, of the saved scan positions are fitted to a surface shape for providing a plane of best focus for the surface under test (66), and the surface under test (66) is automatically positioned (40, 35, 60) relative to the optical system for automatically focusing the object under test (66) across the plane of best focus.
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Chakmakjian Stephen H.
Deck Leslie L.
Turner Samuel A.
Zygo Corporation
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