Sumipro

Metrology

Quality control of parts and surfaces.

Quality control

Quality control of optical parts often involve complicated optical measuring equipment, since touching delicate optical surfaces is not possible. Most of the metrology for optics is therefore based on using light as a measurement probe. With that in mind, do not forget the capabilities of the human eye (sometimes enhanced with lenses) to observe and determine cleanliness and surface finish of optical surfaces.

Our equipment

Measuring devices

MarSurf WI 50M

The MarSurf WI 50M is a powerful surface profiler for the three-dimensional measurement and analysis of surfaces – contactless, independent of material. Precise measurement in the sub-nanometer range. Roughness measurement according to DIN EN ISO 4287 / 25178. Topography measurement (including volume, wear, isotropy). Measurement of microgeometry and layer thicknesses.

Form Talysurf

The Taylor Hobson Talysurf is still the market accepted standard for measuring aspherical surface form errors up to nm’s accuracy. Since interferometric measurement of aspherical surfaces is either impossible or very expensive, we rely on our Talysurf to check our form errors. It is fast and relative easy to use, whereas using interferometers with CGH lenses take long lead times and are very expensive.

Interferometry

With respect to flat optical surface, interferometry is the way to measure accurately the complete surface shape of the part. It gives an 3D height map of the whole surface, whereas the Talysurf only measures in profile line. We can measure up to 6 inch diameter with a transmission flat with PV values > λ/20.

Climate chamber

In order to be able to act quickly for any prototyping need, we can test most ISO/MIL durability requirements in our in-house climate chamber. This one reaches down to -70 ̊C and up to +180 ̊C and can also run humidity tests within 10 % to 95% RH. Cycling according to ISO is of course available as well.

2x Mitutoyo QM height

We use our Mitutoyo height gauges for measuring reference surfaces realibly within 2 to 3 µm accuracy. This is most often the starting point for any diamond turned or fly-cut operation.

Spectrophotometer

Most all of our customers need their own wavelength specific optimal coating design. Whether reflective or anti-reflective, we always tailor our coating stacks to your specification. After doing a trial run, the performance of the coating is measured and compared to design. Sometimes an additional trial run is necessary to improve. For every coating batch, we test the spectral response of the coating and send you a copy of the report.