Fast and reliable in-situ measurements of large and complex surfaces using a novel deflectometric device

R. Kometer; E. Hofbauer

doi:10.1117/12.2318583

7 August 2018 Fast and reliable in-situ measurements of large and complex surfaces using a novel deflectometric device

R. Kometer, E. Hofbauer

Proceedings Volume 10829, Fifth European Seminar on Precision Optics Manufacturing; 108290B (2018) https://doi.org/10.1117/12.2318583
Event: Fifth European Seminar on Precision Optics Manufacturing, 2018, Teisnach, Germany

Abstract

In-situ measurements of complex surfaces during the polishing process is a challenge for the production of aspheric surfaces or freeforms. We are providing a new attempt by using a scanning deflectometric device based on our recently published DaOS [1] principle, which allows in-situ measurements of large optical surfaces in realistic production environments and offers the conditions for direct intervention and correction in the polishing process. The results of insitu surface measurements after three polishing steps of a large glass substrate (320 mm in diameter) in a lever-polishing machine (NLP500 from Stock Konstruktion GmbH) are shown and critically compared with interferometric measurements on a SSI-A Interferometer. In this paper, the technical setup consisting of a highly precise scanning penta prism device and a Vignetting Field Stop (VFS) Sensor is explained. Secondly, we are discussing the mathematical algorithm to reconstruct the complete surface from angle measurements from a given number of cross-sectional cuts. The data of the surface reconstruction are transformed into a XYZ-file format to be analyzed with MetroPro®. The results are shown and discussed in terms of accuracy and reproducibility. Finally, a comparison with interferometric measurements on an SSI-A (QED) at TH Deggendorf (THD), Technology Campus Teisnach is shown to proof the degree of accuracy and applicability of our new, fast and reliable device for in-situ measurements of complex surfaces.

Citation Download Citation

R. Kometer and E. Hofbauer "Fast and reliable in-situ measurements of large and complex surfaces using a novel deflectometric device", Proc. SPIE 10829, Fifth European Seminar on Precision Optics Manufacturing, 108290B (7 August 2018); https://doi.org/10.1117/12.2318583

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

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
7 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Surface finishing

Polishing

Interferometry

Interferometers

Glasses

Aspheric lenses

Prisms

Keywords/Phrases

Search In:

Publication Years