Measuring of aspheres
Interferometric measurements
Stitching Interferometer in vertical arrangement with downward looking Fizeau type interferometric unit. It uses lateral stitching and nulling system. Measured part is fixtured with variable vacuum holder, with a mechanical self centering holder or with the HD chuck holder. It is possible to evaluate shape of measured part or reflected wavefront error.
Measurement features:
- plano, spherical and aspherical polished concave or convex surfaces up to 300 mm in diameter in accuracy up to λ/30,
- aspheres without point of inflection with deparfure from best-fit-sphere up to 1000 λ (650 μm),
- surfaces with numerical aperture up to 1 (full hemispheres),
- spherical surfaces with improved accuracy (thanks to stitching automatical calculating and removing of systematic instrument error),
- radiuses of curvature up to 800 mm,
- form deviation of plano, spherical and aspherical surfaces with capability to exporting data for following correction.