Laboratory for Optical Metrology

The work in the laboratory for optical metrology include the two centers of gravity "in process measuring method" and "process for the edge zone analysis".

In Focus "In process measurement method" is the edited questions focus on the area of ​​the surface judgment means scattered light and other methods as well as the determination of (primarily) mechanical workpiece loads during manufacture.

The light scattering methods used allow for quick, in-process determination of (statistical) surface characteristics, without detecting the actual topography of the component. The procedures can be very quickly investigate moving component surfaces in the manufacturing process. In addition to assessing the mean roughness in the observed measurement spot, statements about structure heights and widths as well as individual defect classes of components are possible. By comparing with rigorous scattering theory based on Maxwell theory this geling not only for the structure area with sizes above the optical wavelength, but also for structures in the nanometer range (below the optical wavelength). In addition to the scattered light method and optical methods (eg. As white light) are researched and developed, which reflect the topography of the component, but are useful because of the low speed measurement only conditionally for in-process applications.

The detection of workpiece loads carried on optically accessible areas of the component surface (e.g., component side when it is processed from the top) and is based on locally-resolution correlation method to determine surface displacements. From these displacements with a resolution in the double-digit nanometer range, the location-dependant strain the surface with high precision can be determined.

Used "process for the edge zone analysis" based on photothermal measuring principles, which correlates with measurement effect material properties of the marginal zone. Based on the measured data, statements with respect to the depth and size of boundary layers and impurities, the thermal conductivity and heat capacity can be derived.

Within the two thematic priorities of the laboratory performs or offers to BIMAQ following services:

  • Feasibility studies on the application of measurement principles, particularly in manufacturing and heat treatment processes
  • Development of measuring methods for concrete, industrial applications
  • Basic research for new measurement methods in the two focal points
  • Simulation and measurement of light scattering on micro- and nano-structured components to assess the structural quality
  • Destructive Randzonen- / Topography checking by comparison with reference samples
  • Standardized Assessment of resistance of laser protection products against laser radiation

The laboratory equipment is spread over several optical measuring rooms with laser protection devices and includes the following systems:

  • Various measuring devices for scattered light-based surface characterization (own developments, measuring ranges: Roughness: 20 nm - 2 microns, measurement frequency: up to 100 Hz)
  • White light interferometer (Agos)
  • Tactile roughness for comparative studies (for example Mitutoyo CS5000, Mahr perthometer, Mahr LD120)
  • Reference measuring system for high-resolution light scatter measurements (in-house development, detected angular range: almost 4π, angular resolution 2 arcsec)
  • Measuring systems for in-process measurement of deformation of components (measurement frequency: up to 180 Hz, lateral resolution: ≈ ​​2 microns, deformation resolution: ≈ ​​60 nm).
  • 2-frequency interferometer (Jenoptik)
  • Various measuring spaces photothermal proximate zone analysis with different laser sources (own developments)
  • Micromagnetics measuring station (3MA) for comparative studies

Contact Details

Dirk Stöbener
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Phone:+49 (0)421 218 646 40