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Proceedings Paper

Efficiently mating fibers to spectrographs
Author(s): Jean P. Brodie; R. Hank Donnelly; Harland W. Epps; Matthew V. Radovan; William W. Craig
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Paper Abstract

We describe the conversion of an existing f/8 Cassegrain spectrograph to a floor-mounted spectrograph fed by 94 fibers from the f/5 prime focus of the Shane 3-meter telescope at Lick Observatory. The spectrography forms part of the automated Multi- Object Spectrograph system developed as a collaboration between UCO/Lick Observatory and the Lawrence Livermore National Laboratory. Fibers from a robotic fiber-positioner at prime focus degrade the f/5.5 beam from the telescope (after it has passed through a wide-field prime focus corrector) into roughly a f/4.5 beam. If the 4/8 spectrograph were fed directly with this f/4.5 beam approximately 68% of the light would be lost. A simple optical system has been designed that converts the light from the fibers into the f/ratio expected by the spectrograph. The conversion optics are mounted at the entrance to the spectrograph. We describe focal ratio degradation tests of a variety of optical fibers and the design of the `pseudoslit' which mounts the fibers in a line at the input to the conversion optics.

Paper Details

Date Published: 1 June 1994
PDF: 10 pages
Proc. SPIE 2198, Instrumentation in Astronomy VIII, (1 June 1994); doi: 10.1117/12.176747
Show Author Affiliations
Jean P. Brodie, UCO/Lick Observatory (United States)
R. Hank Donnelly, UCO/Lick Observatory (United States)
Harland W. Epps, UCO/Lick Observatory (United States)
Matthew V. Radovan, UCO/Lick Observatory (United States)
William W. Craig, Lawrence Livermore National Lab. (United States)

Published in SPIE Proceedings Vol. 2198:
Instrumentation in Astronomy VIII
David L. Crawford; Eric R. Craine, Editor(s)

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