SHSLab

The Shack-Hartmann sensor SHSLab represents a physical realization of a "raytracer". Hereby, the directions of beams are transformed into an array of focal spots by means of a mircolens array. The wavefront aberrations are calculated from the positions of spots via integration. SHSLab is available in several product versions.

By means of a special algorithm, SHSLab is capable to reliably detect extremly curved wavefronts. This opens up an extended field of applications for SHSLab potential users.

Moderate requirements for the light-source

The requirements of the spatial und temporal coherence for the lightsource are quite moderate, i.e., stabilized and narrow-banded lightsources can be avoided.

Since the principle of detection only requires one camera frame, the evaluation of the wavefront can be performed at high speed. The SHSLab is perfectly suitable for workshop environments because it does not require a reference wavefront, it is mechanically robust, and delivers stable results. Nevertheless, the accuracay can be distinctly increased by referencing.

The Hartmann-test was originally applied for the adjustment and testing of optical systems. In the 70ies, compensation methods have been developed for the astronomy. Hereby, the Shack-Hartmann-Sensor measures the wavefront deformations caused by the atmospheric influencs. This allows to improve the quality of pictures by means of active adaptive mirrors in the imaging system.

Deformations of optical wavefronts can be introduced in different ways, e.g., by the light-source itself or by reflection, refraction, or diffraction at optical surfaces or objects. In metrology this enables the user to characterize optical surfaces, components and systems. With certain precautions mechanical components with technical surfaces can also be measured.

The metrological specifications of SHSLab basically differ from those of interferometry. Due to the complexity of many tasks, it has to be examined in detail which methods have to be prefered. Surely, SHSLab will not replace interferometry, but will help to expand our customers' capabilities in research and fabrication.

The software of the SHSLab Basic sensor system has even more functions than only the reconstruction of the measured wavefront. It also contains tools for the calibration of the sensor head and for further analysis of the measured data. The results can be exported to other applications (e.g. text, spreadsheet etc.) either in an appealing graphical form or as pure numerical data.
The SHSLab software can be adapted to special applications by including additional algorithms on customers demand. We also support thedevelopement of task specific solutions of our customers.