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Applied Optics

Applied Optics

APPLICATIONS-CENTERED RESEARCH IN OPTICS

  • Vol. 39, Iss. 13 — May. 1, 2000
  • pp: 2107–2115

Improved vertical-scanning interferometry

Akiko Harasaki, Joanna Schmit, and James C. Wyant  »View Author Affiliations


Applied Optics, Vol. 39, Issue 13, pp. 2107-2115 (2000)
http://dx.doi.org/10.1364/AO.39.002107


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Abstract

We describe a method that combines phase-shifting and coherence-peak-sensing techniques to permit measurements with the height resolution of phase-shifting interferometry without the interval-slope limitation of λ/4 per data sample of phase-shifting interferometry. A five-frame algorithm is used to determine both the best-focus frame position and the fractional phase from the best-focus frame of the correlogram acquired through vertical scanning. The two surface profiles retrieved from the phase and the modulation contrast of the correlograms are compared in the phase-unwrapping process to remove fringe-order ambiguity.

© 2000 Optical Society of America

OCIS Codes
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(120.6650) Instrumentation, measurement, and metrology : Surface measurements, figure
(120.6660) Instrumentation, measurement, and metrology : Surface measurements, roughness
(180.3170) Microscopy : Interference microscopy

History
Original Manuscript: September 10, 1999
Revised Manuscript: February 4, 2000
Published: May 1, 2000

Citation
Akiko Harasaki, Joanna Schmit, and James C. Wyant, "Improved vertical-scanning interferometry," Appl. Opt. 39, 2107-2115 (2000)
http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-39-13-2107


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References

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