Silicon carbide mirror cryogenic distortion testing

David G. Michel

doi:10.1117/12.178601

23 June 1994 Silicon carbide mirror cryogenic distortion testing

David G. Michel

Proceedings Volume 2227, Cryogenic Optical Systems and Instruments VI; (1994) https://doi.org/10.1117/12.178601
Event: SPIE's International Symposium on Optical Engineering and Photonics in Aerospace Sensing, 1994, Orlando, FL, United States

Abstract

A silicon carbide mirror has been holographically tested at cryogenic temperatures in an attempt to determine the level of surface distortion as a function of temperature. The test was conducted using the 1M thermal vacuum holographic test chamber, located at the Hughes El Segundo facility. The mirror was initially tested in February 1993, using full thermal strapping of the mirror blank, this allowed the mirror to reach a temperature of 48 Kelvin (K). Digitization of the holograms showed a distinct parallel pattern on the surface which corresponded to the webs located on the back of the mirror. A second test was conducted in June 1993, using only the thermal shrouds to cool the mirror. Without the thermal straps attached the mirror exhibited significantly different performance. With thermal strapping the mirror figure distortion was 2.15 waves peak-to-valley (P-V), 0.5 waves rms at a temperature of 184 K, when the test was repeated without straps the mirror figure distortion averaged 0.69 waves P-V, 0.15 waves rms at a temperature of 181 K and a measurement wavelength of 0.514 micrometers.

Citation Download Citation

David G. Michel "Silicon carbide mirror cryogenic distortion testing", Proc. SPIE 2227, Cryogenic Optical Systems and Instruments VI, (23 June 1994); https://doi.org/10.1117/12.178601

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