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Title: Absolute calibration of optical flats

Abstract

The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.

Inventors:
Publication Date:
Research Org.:
The Regents of the University of California, Oakland, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1175308
Patent Number(s):
6,876,456
Application Number:
10/256,322
Assignee:
The Regents of the University of California (Oakland, CA) OSTI
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION

Citation Formats

Sommargren, Gary E. Absolute calibration of optical flats. United States: N. p., 2005. Web.
Sommargren, Gary E. Absolute calibration of optical flats. United States.
Sommargren, Gary E. Tue . "Absolute calibration of optical flats". United States. https://www.osti.gov/servlets/purl/1175308.
@article{osti_1175308,
title = {Absolute calibration of optical flats},
author = {Sommargren, Gary E.},
abstractNote = {The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Apr 05 00:00:00 EDT 2005},
month = {Tue Apr 05 00:00:00 EDT 2005}
}

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