Scatter-ratio test for lens surface-quality measurement.
P S Schmitt1, T W Webb, E H Barnett
1Corning Glass Works, Research & Development Laboratories, Corning, New York 14831, USA.
Applied Optics
|August 15, 1983
Summary
The scatter ratio test provides a reliable method for measuring optical lens surface quality. This process control tool effectively detects surface finish changes and correlates with traditional roughness measurements.
Area of Science:
- Optics
- Materials Science
- Metrology
Background:
- Optical lens surface quality is critical for performance.
- Quantitative surface measurement is essential for quality control.
- Existing methods may have limitations in sensitivity or reproducibility.
Purpose of the Study:
- To introduce and validate a scatter ratio test for quantitative optical lens surface quality assessment.
- To demonstrate the test's effectiveness as a process control tool.
- To establish the correlation between scatter ratio measurements and traditional surface roughness metrics.
Main Methods:
- A collimated light beam is focused by the lens onto an opaque spot.
- A detector measures scattered light past the spot.
- The spot is displaced to measure total transmitted energy.
- The scatter ratio is calculated from detector outputs.
Main Results:
- The scatter ratio test is reproducible and operator-insensitive.
- The test effectively detects changes in lens surface finish.
- A clear relationship exists between stylus-measured surface roughness and scatter ratios.
Conclusions:
- The scatter ratio test is a robust and effective method for quantifying optical lens surface quality.
- It serves as a valuable process control tool for monitoring surface finish.
- The test offers a reliable alternative or complement to traditional roughness measurement techniques.
