Grinding, lapping and polishing

What it does

Shaping a crystal goes from coarse to fine. Grinding with diamond tools brings the part to size and shape; lapping on a flat plate with a loose abrasive slurry makes its faces flat and parallel; polishing on soft pads with sub-micron abrasives removes the last scratches and leaves a mirror finish.

Each step removes the damage left by the one before, and the part is measured in between: thickness and parallelism, flatness on the Fizeau interferometer, roughness on the optical profiler, angles on the autocollimators. Working in this loop we control size below the micron and flatness to a few nanometres over hundreds of square centimetres.

The machines take crystals, glass, ceramics and metals. Where the material must also be undamaged below the surface, as in crystals for particle beams, polishing is followed by chemical etching.

What we use it for

• Reference flats and optical surfaces

  Flat references and optics for our own metrology and for partners.

• Crystals for X-ray and γ-ray optics

  Crystal plates with flat, parallel faces for Laue lenses and X-ray optics.

• Substrates for OTELLO

  Super-polished substrates for the OTELLO Laue lens, a project of the European Space Agency.

Working with us

Describe the part, the material and the flatness and roughness you need: we can tell you what we can reach and measure the result with you.