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Applied Optics

Applied Optics


  • Vol. 42, Iss. 31 — Nov. 1, 2003
  • pp: 6245–6254

Wadsworth mount redux: paraboloidal versus spherical gratings

William R. Hunter, Michael P. Kowalski, and Raymond G. Cruddace  »View Author Affiliations

Applied Optics, Vol. 42, Issue 31, pp. 6245-6254 (2003)

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Spherical and paraboloidal diffraction gratings are considered for use on an experiment involving a collection of satelliteborne spectrographs that will investigate astrophysical plasmas in the spectral region from approximately 100 to 300 Å. We shall use eight spectrographs: Wadsworth mounts in near-normal incidence with effective focal lengths of 3 m, each centered on a chosen wavelength in this spectral range. Ray tracings show that paraboloidal gratings used in the Wadsworth mount have a significant increase in resolution over spherical gratings of the same effective focal length, used in the same mounting, as long as the spectral ranges are small (approximately 10% of the central wavelength). This increase in resolution is due to the spatial extent of coma for a paraboloidal grating that is less than the circle of least confusion of spherical gratings.

© 2003 Optical Society of America

OCIS Codes
(050.1950) Diffraction and gratings : Diffraction gratings
(120.6200) Instrumentation, measurement, and metrology : Spectrometers and spectroscopic instrumentation
(260.7200) Physical optics : Ultraviolet, extreme
(350.5400) Other areas of optics : Plasmas
(350.5730) Other areas of optics : Resolution
(350.6090) Other areas of optics : Space optics

Original Manuscript: March 14, 2003
Revised Manuscript: July 23, 2003
Published: November 1, 2003

William R. Hunter, Michael P. Kowalski, and Raymond G. Cruddace, "Wadsworth mount redux: paraboloidal versus spherical gratings," Appl. Opt. 42, 6245-6254 (2003)

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