Paper
11 November 1999 Polished homogeneity testing of Corning fused silica boules
Author Affiliations +
Abstract
Interferometrically measuring the index of refraction variation (index homogeneity) of glass blanks requires that the blanks be made transparent to the interferometer laser. One method for achieving this is to 'sandwich' a rough ground blank between two polished flats while adding an index matching liquid at each surface interface. This is better known as oil-on-flat (OOF) or oil-on-plate testing. Another method requires polishing both surfaces and is better known as polished homogeneity (PHOM) testing or the Schwider method. Corning Inc. historically has used OOF testing to measure the index homogeneity of disk-shaped, fused silica boules over multiple 18' diameter apertures. Recently a boule polishing and PHOM testing process was developed by Corning for measuring the homogeneity over 24' diameter apertures to support fused silica production for the National Ignition Facility (NIF). Consequently, the PHOM technique has been compared to the OOF process using a number of different methods including repeatability/reproducibility studies, data stitching, and vibration analysis. The analysis performed demonstrates PHOM's advantages over OOF testing.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Andrew W Fanning, Joseph F. Ellison, and Daniel E. Green "Polished homogeneity testing of Corning fused silica boules", Proc. SPIE 3782, Optical Manufacturing and Testing III, (11 November 1999); https://doi.org/10.1117/12.369224
Lens.org Logo
CITATIONS
Cited by 1 scholarly publication.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Polishing

Silica

Wavefronts

Surface finishing

Interferometers

Reflection

Time metrology

Back to Top