Optics: measuring and testing – By particle light scattering – With photocell detection
Patent
1993-02-24
1995-04-04
Limanek, Robert P.
Optics: measuring and testing
By particle light scattering
With photocell detection
356345, 356358, G01B 902, G01B 1102
Patent
active
054042216
ABSTRACT:
A method and apparatus for distance measurement includes an optical interferometer, a two-color source characterized by a synthetic wavelength, and processing means for acquiring and analyzing phase information. The synthetic wavelength, which corresponds to the spatial period of phase coincidence in two-color interferometry, is commonly used in metrology to increase the unambiguous distance-measurement range. The invention provides a greatly enhanced unambiguous measurement range, for a given synthetic wavelength, over the unambiguous range of prior-art techniques. This extended range is achieved by analysis of a phase couple formed by a combination of the synthetic and optical phases. This phase couple repeats at spatial intervals which may be very much larger than the synthetic wavelength. Detailed computational methods for illumination source selection and for data analysis are provided, and several specific embodiments of the invention are described.
REFERENCES:
patent: 3171881 (1965-03-01), Morokuma
patent: 3398287 (1968-08-01), Krogstad et al.
patent: 3523735 (1970-08-01), Taylor
patent: 3572935 (1971-03-01), Howell
patent: 4355899 (1982-10-01), Nussmeier
patent: 5096296 (1992-03-01), Lu
patent: 5164789 (1992-11-01), Yoshitake et al.
patent: 5268739 (1993-12-01), Martinelli et al.
patent: 5285252 (1994-02-01), Vareille et al.
Wyant, J. C., "Testing Aspherics Two-Wavelength Holography", Applied Optics, Sep. 1971 vol. 10, No. 9.
Fercher, A. F., Hu, H. Z. and Vry, U., "Rough Surface Interferometry With A Two-Wavelength Heterodyne Speckle Interferometer", Applied Optics, 15 Jul. 1985, vol. 24, No. 14.
Cheng, Yeou-Yen and Wyant, James C., "Two-Wavelength Phase Shifting Interferometry", Applied Optics, 15 Dec. 1984, vol. 23, No. 24.
Tilford, Charles R., "Analytical Procedure For Determining Lengths From Fractional Fringes", Applied Optics, Jul. 1977, vol. 16, No. 7.
Massie, N. A. (Bert) and Caulfield, H. John "Absolute Distance Interferometry", Interferometric Metrology, SPIE vol. 816, 1987.
Haines, K. and Hildebrand, B. P., "Contour Generation By Wavefront Reconstruction", Physics Letters, 15, Sep. 1965, vol. 19, No. 1.
Hariharan, P., Oreb B. F., Eiju, T., "Digital Phase-Shifting Interferometry: A Simple Error-Compensating Phase Calculation Algorithm", Applied Optics, 1 Jul. 1987, vol. 26, No. 13.
Born, M. and E. Wolf Principles of Optics, Pergamon Press, 1987.
Limanek Robert P.
Ostrowski David
Zygo Corporation
LandOfFree
Extended-range two-color interferometer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Extended-range two-color interferometer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extended-range two-color interferometer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2383325