Scanning pentaprism test for the GMT 8.4 m off-axis segments

Richard Allen, Peng Su, James H. Burge, Brian Cuerden, Hubert M. Martin

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

14 Scopus citations

Abstract

The scanning pentaprism system for testing the 8.4 m off-axis segments for the Giant Magellan Telescope has recently been completed. The system uses a fiber source and a carriage mounted pentaprism to scan a 40 mm collimated beam across the surface of the segment under test. Since the scanning beam is parallel to the optical axis of the parent mirror, it comes to focus on a detector at the telescope's prime focus, where displacement of the spot is proportional to the slope error. A second collimated beam from a stationary reference pentaprism is used to compensate for any changes in the relative positions of the optical components during testing. The optical components are suspended over the mirror on a rail system that can be rotated so that scans can be made across any diameter of the segment. The test is capable of measuring wavefront slope errors to 1 μrad rms, adequate to verify that power, astigmatism, coma, and other low-order aberrations are small enough to be corrected easily at the telescope with the segment's active support system.

Original languageEnglish (US)
Title of host publicationModern Technologies in Space- and Ground-Based Telescopes and Instrumentation
DOIs
StatePublished - Sep 23 2010
EventModern Technologies in Space- and Ground-Based Telescopes and Instrumentation - San Diego, CA, United States
Duration: Jun 27 2010Jul 2 2010

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume7739
ISSN (Print)0277-786X

Other

OtherModern Technologies in Space- and Ground-Based Telescopes and Instrumentation
CountryUnited States
CitySan Diego, CA
Period6/27/107/2/10

Keywords

  • Aspherics
  • Optical testing
  • Telescope

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Scanning pentaprism test for the GMT 8.4 m off-axis segments'. Together they form a unique fingerprint.

  • Cite this

    Allen, R., Su, P., Burge, J. H., Cuerden, B., & Martin, H. M. (2010). Scanning pentaprism test for the GMT 8.4 m off-axis segments. In Modern Technologies in Space- and Ground-Based Telescopes and Instrumentation [773911] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 7739). https://doi.org/10.1117/12.857901