Optical surfacing of one-meter-class reaction bonded silicon carbide

Robert S. Breidenthal; Regina Galat-Skey; John J. Geany

doi:10.1117/12.225297

23 October 1995 Optical surfacing of one-meter-class reaction bonded silicon carbide

Robert S. Breidenthal, Regina Galat-Skey, John J. Geany

Proceedings Volume 2543, Silicon Carbide Materials for Optics and Precision Structures; (1995) https://doi.org/10.1117/12.225297
Event: SPIE's 1995 International Symposium on Optical Science, Engineering, and Instrumentation, 1995, San Diego, CA, United States

Abstract

Optical fabrication methods for a one meter reaction bonded optical grade silicon carbide (RBO SiC) substrate have been successfully developed and demonstrated by Itek Optical Systems in Lexington, Massachusetts. A 1.125 m multiplied by .825 m RBO SiC panel, the largest SiC ever fabricated, has been ground and polished to a surface figure of lambda/20 rms at lambda equals .6328 nm. The single most critical technology area for RBO SiC optics has been attaining a high quality optical surface finish; this bimodal material requires particular processing techniques due to the hardness differences between the silicon and silicon carbide components. The measured surface finish quality for this one meter mirror is 15.5 angstrom rms, nearly twice as good as the specified 25 angstrom rms. Furthermore, the variation of surface finish over the mirror area is very low, sigma equals 2 angstrom. The mirror represents the state-of-the-art for lightweight, high quality SiC optical mirrors.

Citation Download Citation

Robert S. Breidenthal, Regina Galat-Skey, and John J. Geany "Optical surfacing of one-meter-class reaction bonded silicon carbide", Proc. SPIE 2543, Silicon Carbide Materials for Optics and Precision Structures, (23 October 1995); https://doi.org/10.1117/12.225297

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