Optical Work on Unusually Large Glass Plates. An Interface Method of Investigating High-Quality Flat Surfaces
Abstract
The problem of determining quantitatively the exact surface contour of large glass plates is essentially a problem of obtaining a large and accurately flat reference surface on which to base the measurements. A measuring method is described which may be employed to obtain the contour measurements of glass plates of any practical size. A thin liquid layer, for example, water, covers the plate to be investigated. The liquid layer provides the flat and always horizontal reference plane from which quantitative contour measurements may be made. Interference phenomena - lines of constant distance from the reference surface - are produced due to reflections on the liquid layer and the plate surfaces. True surface contour pictures may then be taken in one operation. Quantitative surface measurements can be calculated from the pictures by employing known light wave length.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1950
- Accession Number
- ADA377626
Entities
People
- Ferdinand M. Mirus
- Theodor W. Zobel