Micromeasurements on smooth surfaces with a new confocal optical profiler

Ferran Laguarta; Roger Artigas; Agusti Pinto; I. Al-Khatib

doi:10.1117/12.334329

29 December 1998 Micromeasurements on smooth surfaces with a new confocal optical profiler

Ferran Laguarta, Roger Artigas, Agusti Pinto, I. Al-Khatib

Proceedings Volume 3520, Three-Dimensional Imaging, Optical Metrology, and Inspection IV; (1998) https://doi.org/10.1117/12.334329
Event: Photonics East (ISAM, VVDC, IEMB), 1998, Boston, MA, United States

Abstract

The surface metrology market toady is moving towards non- contact modular computer-controlled system for measuring and analyzing roughness, contour and topography. In this paper we present a new optical instrument based on the concept of confocal microscopy. In this instrument, which is especially suitable for measurements on smooth surfaces, either a pinhole or a structured light pattern in imaged by a very high numerical aperture optical system on the surface of the sample to be measured. The reflected light is observed wit a CCD array and analyzed with different image data processing algorithms. Two different experimental prototypes were developed to allow the measurement not only of surfaces with good accessibility but also of those with intricate geometries, difficult access and small dimensions. Various samples such as high precision optical surfaces, master gratings, and diamond drawing dies were measured. All the results obtained show that the confocal optical profiler is robust enough to provide a surface topography with spatial resolution lower than 1 micrometers and uncertainty about 10 nm. In addition to the replacement of the existing stylus system, there are also important new potential applications for this kind of instrument.

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Ferran Laguarta, Roger Artigas, Agusti Pinto, and I. Al-Khatib "Micromeasurements on smooth surfaces with a new confocal optical profiler", Proc. SPIE 3520, Three-Dimensional Imaging, Optical Metrology, and Inspection IV, (29 December 1998); https://doi.org/10.1117/12.334329

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