Meter-class mirror figure metrology using a 24-channel fiber interferometer

Ronald Holzlöhner; Samuel Lévêque; Nicola Di Lieto; Juan-Antonio Marrero Hernández; Andrew P. Rakich

doi:10.1117/12.2312642

10 July 2018 Meter-class mirror figure metrology using a 24-channel fiber interferometer

Ronald Holzlöhner, Samuel Lévêque, Nicola Di Lieto, Juan-Antonio Marrero Hernández, Andrew P. Rakich

Proceedings Volume 10706, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation III; 107061F (2018) https://doi.org/10.1117/12.2312642
Event: SPIE Astronomical Telescopes + Instrumentation, 2018, Austin, Texas, United States

Abstract

We measured the influence functions of a 9-actuator warping harness of an ELT primary mirror segment prototype using a fiber interferometer. The compact setup consists of a stiff, lightweighted aluminium plate with a similar diameter as the segment (1.25 m), holding 24 fiber-fed collimators arranged in three concentric rings. We measure simultaneously the 24 absolute distances to the mirror surface with a nominal precision of 0.5 ppm. The recorded noise level in a quiet environment was below 50 nm rms. We found good agreement between the measured influence functions and the finiteelement model by the segment support manufacturer. These measurements were performed at ESO Garching in June 2017, with the “Absolute Multiline” metrology system.

Conference Presentation

Citation Download Citation

Ronald Holzlöhner, Samuel Lévêque, Nicola Di Lieto, Juan-Antonio Marrero Hernández, and Andrew P. Rakich "Meter-class mirror figure metrology using a 24-channel fiber interferometer", Proc. SPIE 10706, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation III, 107061F (10 July 2018); https://doi.org/10.1117/12.2312642

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