Measurement of aspheric mirror segments using Fizeau interferometry with CGH correction

James H. Burge; Chunyu Zhao; Matt Dubin

doi:10.1117/12.857816

19 July 2010 Measurement of aspheric mirror segments using Fizeau interferometry with CGH correction

James H. Burge, Chunyu Zhao, Matt Dubin

Proceedings Volume 7739, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation; 773902 (2010) https://doi.org/10.1117/12.857816
Event: SPIE Astronomical Telescopes + Instrumentation, 2010, San Diego, California, United States

Abstract

Large aspheric primary mirrors are proposed that use hundreds segments that all must be aligned and phased to approximate the desired continuous mirror. We present a method of measuring these concave segments with a Fizeau interferometer where a spherical convex reference surface is held a few millimeters from the aspheric segment. The aspheric shape is accommodated by a small computer generated hologram (CGH). Different segments are measured by replacing the CGH. As a Fizeau test, nearly all of the optical elements and air spaces are common to both the measurement and reference wavefront, so the sensitivities are not tight. Also, since the reference surface of the test plate is common to all tests, this system achieves excellent control for the radius of curvature variation from one part to another. This paper describes the test system design and analysis for such a test, and presents data from a similar 1.4-m test performed at the University of Arizona.

Citation Download Citation

James H. Burge, Chunyu Zhao, and Matt Dubin "Measurement of aspheric mirror segments using Fizeau interferometry with CGH correction", Proc. SPIE 7739, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation, 773902 (19 July 2010); https://doi.org/10.1117/12.857816

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available