Corning 7972 ULE material for segmented and large monolithic mirror blanks

Robert Sabia; Mary J. Edwards; Randy VanBrocklin; Bruce Wells

doi:10.1117/12.672059

6 July 2006 Corning 7972 ULE material for segmented and large monolithic mirror blanks

Robert Sabia, Mary J. Edwards, Randy VanBrocklin, Bruce Wells

Proceedings Volume 6273, Optomechanical Technologies for Astronomy; 627302 (2006) https://doi.org/10.1117/12.672059
Event: SPIE Astronomical Telescopes + Instrumentation, 2006, Orlando, Florida , United States

Abstract

Ultra-Low Expansion (ULE^®) glass has been and continues to be a significant material for astronomical applications. With a nominal composition of 7 wt. %TiO₂ in SiO₂, Corning Code 7972 ULE^® has a mean room temperature coefficient of thermal expansion (CTE) of 0 ± 30 ppb/°C with a typical CTE range of less than 15 ppb/°C, properties vital to the manufacture of high resolution optics requiring extreme thermal stability. Combined with lightweighting techniques developed at Corning during the past 30 years, ULE^® has been successfully employed for numerous monolithic and lightweight mirror applications including the 2.4 meter Hubble Space Telescope lightweight primary mirror, the Airborne Laser (ABL) primary mirrors, and most recently the Discovery Channel Telescope 4 meter mirror blank. ULE^® maintains its strong candidacy for future ELT applications. Recent challenges in mirror surface specifications and the development of alternative material choices calls for a comparison with ULE^®. The objective of this article is to review ULE^® properties and manufacturing capabilities, and to compare relevant material properties to those of alternative material options, thus allowing designers to properly execute material selection. Finally, recent development efforts directed toward improving ULE^® will be discussed.

Citation Download Citation

Robert Sabia, Mary J. Edwards, Randy VanBrocklin, and Bruce Wells "Corning 7972 ULE material for segmented and large monolithic mirror blanks", Proc. SPIE 6273, Optomechanical Technologies for Astronomy, 627302 (6 July 2006); https://doi.org/10.1117/12.672059

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