Spin-cast Zerodur mirror substrates of the 8-m class and lightweighted substrates for secondary mirrors

Rudolf W. Mueller; Hartmut W. Hoeness; Thomas A. Marx

doi:10.1117/12.19242

1 July 1990 Spin-cast Zerodur mirror substrates of the 8-m class and lightweighted substrates for secondary mirrors

Rudolf W. Mueller, Hartmut W. Hoeness, Thomas A. Marx

Proceedings Volume 1236, Advanced Technology Optical Telescopes IV; (1990) https://doi.org/10.1117/12.19242
Event: SPIE Astronomical Telescopes and Instrumentation for the 21st Century, 1990, Tucson, AZ, United States

Abstract

For about 20 years SCHOTT has been supplying the glass ceramic ZERODUR, a material with a thermal expansion of virtually zero. ZERODUR is excellently suited for the manufacture of mirror substrates for astronomical telescopes. SCHOTT has accumulated substantial experience in melting and processing of this material. New techniques, such as spin-casting, have been developed by SCHOTT for the manufacture of thin monolithic mirror blanks exceeding 8 m in diameter. These developments resulted in SCHOTT obtaining the order for the manufacture of 4 meniscus shaped shells for the Very Large Telescope of the European Southern Observatory. The corresponding production facilities are currently being erected with the first casting scheduled for the end of 1990. SCHOTT has also performed considerable developmental work in the area of lightweighted ZERODUR mirror substrates which can be fabricated by applying one or a combination of the following techniques: forming of the lightweighted structure during casting, fusion of individual components to a total structure and lightweighting of a massive block by various machining methods.

Citation Download Citation

Rudolf W. Mueller, Hartmut W. Hoeness, and Thomas A. Marx "Spin-cast Zerodur mirror substrates of the 8-m class and lightweighted substrates for secondary mirrors", Proc. SPIE 1236, Advanced Technology Optical Telescopes IV, (1 July 1990); https://doi.org/10.1117/12.19242

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