Two-wavelength phase-shifting interferometer and method

Details Two-wavelength phase-shifting interferometer and method Two-wavelength phase-shifting interferometer and method

1986-03-19

1989-05-23

Willis, Davis L.

Optics: measuring and testing

By dispersed light spectroscopy

Utilizing a spectrometer

356360, G01B 902

Patent

active

048324892

ABSTRACT:
An improved apparatus and method are described for accurately "reconstructing" steep surface profiles, such as for aspheric surfaces, using improved two-wavelength phase-shifting interferometry, wherein single-wavelength precision is obtained over surfaces having departures of hundreds of visible wavelengths from a reference surface. The disclosed technique avoids cumulative summing of detector errors over a large detector array by computing the "equivalent" phase for each detector independently of the intensities of other detectors. Inaccurate phase data points having an equivalent fringe contrast less than a predetermined threshold are eliminated from data from which contour maps of the aspheric surface are displayed or plotted.

REFERENCES:
patent: 3694088 (1972-09-01), Gallagher et al.
patent: 4225240 (1980-09-01), Balasubramanian
Wyant, Applied Optics, vol. 10, No. 9, Sep. 1971, pp. 2113-2118, "Testing Aspherics Using Two-Wavelength Holography".
Creath et al., Optica Acta, vol. 32, No. 12, pp. 1455-1464, "Contouring Aspheric Surfaces Using Two-Wavelength Phase Shifting Interferometry".
Cheng, "Multiple-Wavelength Phase Shifting Interferometry", Dissertation, University of Arizona, 1985.
"Two-Wavelength Phase Shifting Interferometry", Cheng and Wyant, Applied Optics, Dec. 1984, vol. 23, No. 24.
"Digital Wave-Front Measuring Interferometry: Some Systematic Error Sources", Schwider et al., Applied Optics, Nov. 1983, vol. 22, No. 21.
"An Optical Profilometer for Surface Characterization of Magnetic Media", Wyant et al., 38th Annual Meeting in Houston, TX.
"Use of an AC Heterodyne Lateral Shear Interferometer With Real-Time Wavefront Correction Systems", Wyant, Applied Optics, vol. 14, No. 11, Nov. 1975.

Affiliated with

Also associated with

Rating

Two-wavelength phase-shifting interferometer and method does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Two-wavelength phase-shifting interferometer and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-wavelength phase-shifting interferometer and method will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1726635