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.

3D proflometric measurements

3D non-contact profilometer for measuring of rotationally symetric shapes. Spheres and aspheres with- and without point of inflection. Measured part is fixtured with a mechanical self centering holder or with the HD chuck holder.

Measurement features:

  • plano, rotationally symetric spherical and aspherical polished and opaque concave or convex surfaces up to 260 mm in diameter in accuracy up to 50 nm
  • surfaces with numerical aperture up to 1 (full hemispheres)
  • any radiuses of curvature
  • form deviation of plano, spherical and aspherical surfaces with capability to exporting data for following correction
     

2D proflometric measurements

2D contact profilometer for measuring of profiles of different shapes, angles, steep steps etc. Measured part is laying on adjustable table, fixtured with a mechanical self centering holder or with the HD chuck holder.

Measurement features:

  • plano, spherical and aspherical polished and ground concave or convex surfaces up to 200 mm in diameter in accuracy up to 0,2 um
  • height of steep steps, coatings etc.
  • roughtness evaluation
  • any radiuses od curvature
  • maximum sample height 47 mm (depends on used stylus length)
  • form deviation of plano, spherical and aspherical surfaces with capability to exporting data for following correction