Measurement and sensor technology
We research and develop novel optical measurement techniques and sensors with the aim of outperforming existing products on the market in terms of speed, sensitivity or accuracy.
If you as a user have special requirements or as a manufacturer would like to develop a new product: please contact us.
Confocal optics can be used to precisely detect the surface of non-cooperative objects, regardless of whether it is reflective, (volume) scattering or transparent. Developed and patented by us: a multifocal confocal system with hyperchromatic objective. With this system, more than 1200 3D measuring points can be acquired simultaneously within one image without moving elements.
Fringe projection is a widely used method for measuring topography. However, with volume-scattering objects, errors occur which can be corrected by taking the light propagation into account. With this now "model-based fringe projection" it is also possible to obtain a wide range of properties of the surface and from the interior of the object.
At the institute, both in-house interferometric developments and commercial devices for topography determination and dynamic deformation measurement of scattering and reflecting surfaces are available. The achievable measurement uncertainty is in the sub-µm range, whereby the measurement range can be several mm.
With a normal color camera, three color channels (RGB) are captured per pixel, with hyperspectral imaging it can be several hundred. At the ILM, we have developed a system that captures 2500 pixels in one image with a spectral resolution of 120 pixels. We have now also developed a micro-optical version with a depth of only 10 mm.
The composition of the irradiated sample can be qualitatively determined by absorption or fluorescence spectroscopy. Our special feature: by a complete modelling of the light paths, the influence of light scattering is eliminated and the concentration of the components is quantitatively determined, without any calibration.
The scattering of light on small particles is determined by their size, shape and refractive index. To obtain this information, a measured scattered light distribution must be compared with model calculations for different parameters and the most suitable combination must be found - which is not trivial. The ILM has developed particularly fast programmes for this purpose.
In photothermal materials testing, the component is heated in a pulsed or modulated manner and the surface temperature is measured with time or phase resolution. In this way, material properties can be determined contact-free and non-destructive with depth resolution, e.g. hardness or porosity. In layered systems, thicknesses can be measured or adhesion defects can be detected.
