Translator Disclaimer
26 June 2017 Preliminary results of a new proposal for objective human independent striae measurement
Author Affiliations +
Optical glasses with certain inner quality e.g. low striae content are essential for good optical systems. A stria is a small local change in the refractive index inside the glass resulting in a wave front distortion that can cause blurring of the image. During the production process of optical glass, striae are observed by measuring it with the so-called shadow graph method. This simple measurement displays a stria as a shadow on an observation screen. A human operator evaluates the contrast by comparing it with references. The new proposed approach uses a digital camera and image processing to measure human independent the stria level. A first repeatability measurement shows wave front deviation (maximum deviation, peak-topeak) of less than +/- 8 nm.
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
S. Reichel, P. Hartmann, U. Petzold, and C. Lempa "Preliminary results of a new proposal for objective human independent striae measurement", Proc. SPIE 10329, Optical Measurement Systems for Industrial Inspection X, 103291I (26 June 2017);

Back to Top