Optical Metrology

We develop industrial measuring and testing systems for the quality control of coatings and materials such as liquids and organic substances. Science, technology and engineering rely on our expertise in the following areas:

  • Optical system and measurement technology
  • Spectroscopy
  • Development of crystal and semiconductor components

The technologies range from optical coherence tomography (OCT) in the visible spectral range to time domain spectroscopy in the terahertz frequency range and electronic system concepts in the millimeter wave range. We adapt our systems individually for our customers. This includes both the application software and the evaluation software, which clearly displays the essential target values. Throughout the entire development process, our customer companies benefit from the process understanding of our employees.

We use the following techniques:

  • White light interferometry
    • Wavelength range: 400 nm – 1600 nm
    • Thickness measurement on transparent layers
  • Spectroscopy
    • Frequency range: UV, VIS, IR, Terahertz
    • Substance identification
  • Hyperspectral imaging
    • Wavelength range: 1200 – 2200 nm
    • Substance identification

Optical Coherence Tomography (OCT)

Functional properties require a minimum thickness because unnecessarily thick layers waste resources and increase manufacturing costs. There is now a solution for measuring very thin, semitransparent layers: Optical Coherence Tomography (OCT). This method was originally developed for the depth-resolved visualization of biological and medical materials.

Thanks to intensive research, it has now also established itself outside medicine. High-resolution sample cross-sections – which are generated in real time with visible light or infrared light and completely non-destructively – make OCT the ideal non-contact inspection technology for many applications.

 

Classical Spectroscopy and Hyperspectral Imaging

In spectroscopy it is primarily investigated how the sample to be examined changes the spectrum of the incident light. Based on these changes, we draw conclusions about the substance under test and can even identify them in the best case. The term "light" is a synonym for any part of the electromagnetic spectrum, from UV to visual to infrared (NIR, SWIR, LWIR) and Terahertz.

The observed spectrum changes can be caused by absorption, emission, fluorescence and the Raman effect. Transmission, reflection and ATR can be used as measurement arrangements. While in "classical" spectroscopy samples are examined selectively, in hyperspectral imaging sample images with at least 100 spectral channels are recorded. Automated, chemometric evaluation methods support the interpretation of the spectra.

Example Project

 

Coating Thickness of Enameled Wire

Enameled wire is used for the construction of electric coils and transformers. We measure the layer thickness of the insulating varnish on fine and ultrafine wire without contact.

 

Hyperspectral Imaging for Tomatoes

Using hyperspectral imaging, we determine, for example, the BRIX or sugar concentration of tomatoes, which allows conclusions to be drawn about the degree of ripeness – important information for the food industry.