Large, lightweight, low-scatter, composite active/adaptive mirror development

H. E. Bennett; H. F. Blazek; A. O. Danielson

doi:10.1117/12.687503

29 August 2006 Large, lightweight, low-scatter, composite active/adaptive mirror development

H. E. Bennett, H. F. Blazek, A. O. Danielson

Proceedings Volume 6306, Advanced Wavefront Control: Methods, Devices, and Applications IV; 63060Q (2006) https://doi.org/10.1117/12.687503
Event: SPIE Optics + Photonics, 2006, San Diego, California, United States

Abstract

A one meter diameter prototype lightweight composite mirror is being developed. The mandrel on which the composite mirror will be laid up is an ultra low expansion quartz glass, TSG, whose thermal expansion coefficient, 10^-7/°C or less, is similar to that for the composite material. A precise layup procedure for the composite material is required to obtain this coefficient of expansion. The mandrel surface will be superpolished to 6-8 Å rms or better, resulting in ten times less scattered light in the visible region than displayed by a typical astronomical mirror. It has been shown experimentally that mandrel microroughnesses of this order can be successfully transferred to a replicated composite mirror faceplate. The composite faceplate is one to three millimeters thick, very tough, and unlike thin glass adaptive optic faceplates does not fracture easily. Actuators designed for atmospheric correction of the thinner adaptive optic faceplates have a response time of 1/2 msec, which is fast enough to correct for all atmospheric distortion. The thicker faceplates are used for active mirrors and are mounted differently. Controlled by stepper motors they can be used for computer controlled remote focusing over long distances or fine tuning of mirror tip-tilt as well as for gravitational sag of other mirrors in the optical train. All mirror actuators operate in the 30-70 v range.

Citation Download Citation

H. E. Bennett, H. F. Blazek, and A. O. Danielson "Large, lightweight, low-scatter, composite active/adaptive mirror development", Proc. SPIE 6306, Advanced Wavefront Control: Methods, Devices, and Applications IV, 63060Q (29 August 2006); https://doi.org/10.1117/12.687503

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