Multiwavelength digital holography for polishing tool shape measurement

Vít Lédl; Pavel Psota; Jan Václavík; Roman Doleček; Petr Vojtíšek

doi:10.1117/12.2030004

15 October 2013 Multiwavelength digital holography for polishing tool shape measurement

Vít Lédl, Pavel Psota, Jan Václavík, Roman Doleček, Petr Vojtíšek

Proceedings Volume 8884, Optifab 2013; 88840E (2013) https://doi.org/10.1117/12.2030004
Event: SPIE Optifab, 2013, Rochester, New York, United States

Abstract

Classical mechano-chemical polishing is still a valuable technique, which gives unbeatable results for some types of optical surfaces. For example, optics for high power lasers requires minimized subsurface damage, very high cosmetic quality, and low mid spatial frequency error. One can hardly achieve this with use of subaperture polishing. The shape of the polishing tool plays a crucial role in achieving the required form of the optical surface. Often the shape of the polishing tool or pad is not known precisely enough during the manufacturing process. The tool shape is usually premachined and later is changed during the polishing procedure. An experienced worker could estimate the shape of the tool indirectly from the shape of the polished element, and that is why he can achieve the required shape in few reasonably long iterative steps. Therefore the lack of the exact tool shape knowledge is tolerated. Sometimes, this indirect method is not feasible even if small parts are considered. Moreover, if processes on machines like planetary (continuous) polishers are considered, the incorrect shape of the polishing pad could extend the polishing times extremely. Every iteration step takes hours. Even worse, polished piece could be wasted if the pad has a poor shape. The ability of the tool shape determination would be very valuable in those types of lengthy processes. It was our primary motivation to develop a contactless measurement method for large diffusive surfaces and demonstrate its usability. The proposed method is based on application of multiwavelength digital holographic interferometry with phase shift.

Citation Download Citation

Vít Lédl, Pavel Psota, Jan Václavík, Roman Doleček, and Petr Vojtíšek "Multiwavelength digital holography for polishing tool shape measurement", Proc. SPIE 8884, Optifab 2013, 88840E (15 October 2013); https://doi.org/10.1117/12.2030004

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