Abstract

A new modified fused-silica glass whose coefficient of thermal expansion at 20°C is less than $\frac{1}{25}$ that of fused silica is described. It should be particularly useful for large, first-surface mirrors and in other applications where extremely low expansion is desirable. Both solid and lightweight telescope mirror blanks can be constructed using fusion techniques. A discussion of a number of physical properties is included.

© 1968 Optical Society of America

Glass-Ceramics for High Precision Reflective-Optic Applications

D. A. Duke and G. A. Chase
Appl. Opt. 7(5) 813-817 (1968)

Applied Optics at Corning Glass Works

C. J. Parker
Appl. Opt. 7(5) 735-743 (1968)

Thermal expansion uniformity of materials for large telescope mirrors

Stephen F. Jacobs, Dean Shough, and Cliff Connors
Appl. Opt. 23(23) 4237-4244 (1984)

High Precision Photoelastic and Ultrasonic Techniques for Determining Absolute and Differential Thermal Expansion of Titania–Silica Glasses

Henry E. Hagy
Appl. Opt. 12(7) 1440-1446 (1973)

Comparison of two high-precision nondestructive measurement methods for evaluating thermal expansion differences in the 8.3-m ultralow-expansion Subaru primary mirror blank

Henry E. Hagy and Michael E. Best
Appl. Opt. 35(7) 1126-1128 (1996)