WIYN bench upgrade: A revitalized spectrograph

M. Bershady, S. Bardenb, P. A. Blanche, D. Blancod, C. Corsond, S. Crawford, J. Glaspey, S. Habraken, G. Jacoby, J. Keyes, P. Knezek, P. Lemaire, M. Liang, E. McDougall, G. Poczulp, D. Sawyer, K. Westfall, D. Willmarth

Research output: Chapter in Book/Report/Conference proceedingConference contribution

15 Scopus citations


We describe the redesign and upgrade of the versatile fiber-fed Bench Spectrograph on the WIYN 3.5m telescope. The spectrograph is fed by either the Hydra multi-object positioner or integral-field units (IFUs) at two other ports, and can be configured with an adjustable camera-collimator angle to use low-order and echelle gratings. The upgrade, including a new collimator, charge-coupled device (CCD) and modern controller, and volume-phase holographic gratings (VPHG), has high performance-to-cost ratio by combining new technology with a system reconfiguration that optimizes throughput while utilizing as much of the existing instrument as possible. A faster, all-refractive collimator enhances throughput by 60%, nearly eliminates the slit-function due to vignetting, and improves image quality to maintain instrumental resolution. Two VPH gratings deliver twice the diffraction efficiency of existing surface-relief gratings: A 740 l/mm grating (float-glass and post-polished) used in 1st and 2nd-order, and a large 3300 l/mm grating (spectral resolution comparable to the R2 echelle). The combination of collimator, high-quantum efficiency (QE) CCD, and VPH gratings yields throughput gain-factors of up to 3.5.

Original languageEnglish (US)
Title of host publicationGround-based and Airborne Instrumentation for Astronomy II
StatePublished - 2008
EventGround-based and Airborne Instrumentation for Astronomy II - Marseille, France
Duration: Jun 23 2008Jun 28 2008

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherGround-based and Airborne Instrumentation for Astronomy II


  • CCD performance
  • Fiber-fed spectrograph design
  • Volume phase holographic grating

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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