CGH null test design and fabrication for off-axis aspherical mirror tests

Min Wang; Daniel Asselin; Patrice Topart; Jonny Gauvin; Philippe Berlioz; Bernd Harnisch

doi:10.1117/12.692234

12 July 2006 CGH null test design and fabrication for off-axis aspherical mirror tests

Min Wang, Daniel Asselin, Patrice Topart, Jonny Gauvin, Philippe Berlioz, Bernd Harnisch

Proceedings Volume 6342, International Optical Design Conference 2006; 63421Y (2006) https://doi.org/10.1117/12.692234
Event: International Optical Design Conference 2006, 2006, Vancouver, BC, Canada

Abstract

A null-lens based on a Computer Generated Hologram (CGH) is designed to test the primary off-axis aspherical mirror of the GAIA space telescope. This custom-designed and fabricated CGH includes five zones (null CGH, alignment CGH, and beam-projection CGH) on the same substrate. The optical test configuration is simple and the designed five-zones CGHs can simultaneously provide the aberrated wavefront correction for null tests, CGH alignment with a commercial interferometer, pre-positioning of the mirror under test in a cryogenic chamber, and isolation of the diffraction orders in the test setup. Positioning of the five zones with respect to each other is extremely critical for the success of this custom-made CGH null testing. For this reason, the fringes of all five zones were manufactured on a single photolithographic mask. With INO's special micro-fabrication processes, including its photolithographic, etching, and coating technologies, this 4.5-inch in diameter CGH was successfully made. The RMS wavefront error is estimated at 7.33 nm for the fabricated null CGH.

Citation Download Citation

Min Wang, Daniel Asselin, Patrice Topart, Jonny Gauvin, Philippe Berlioz, and Bernd Harnisch "CGH null test design and fabrication for off-axis aspherical mirror tests", Proc. SPIE 6342, International Optical Design Conference 2006, 63421Y (12 July 2006); https://doi.org/10.1117/12.692234

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